Matching metastructure for data modeling

ABSTRACT

A metastructure for representing and manipulating or analyzing a data model is provided herein. A source representation of the first data model may be received. The source representation may include a representation of one or more structural components of the first data model, respectively having identifiers and types. One or more instances of a metastructure schema object datatype may be generated based on the one or more structural components of the source representation. Generating a given instance of the metastructure schema object datatype for a given structural component may include assigning a first identifier of the given structural component to the first data member of the given instance, determining a first type associated with the given structural component, and assigning the first type to the second data member of the given instance. The one or more instances of the metastructure schema object datatype may be stored in association.

FIELD

The present disclosure generally relates to data model structuring anddata model analysis. Particular implementations relate to metastructuresfor data models such as database schemas, and systems and methods forconverting data models to a common metastructure and analyzing datamodels converted to a common metastructure, such as for database mappingor clustering.

BACKGROUND

Enterprise data models and database schemas are often very large andvery complex, and may consist of thousands of entities, attributes, andrelations among the entities and attributes. Further, entities often usemultiple data models across many different systems. Because of thiscomplexity and the wide usage of different data models in varyingsystems, it is often very difficult to make systems interoperable or todevelop or maintain consist information about correlations between thesecomplex data models. This problem is made worse when the data model isundocumented or poorly documented, which is often the case. Such a lackof understandable information makes many tasks using the data modeldifficult, such as system integration or matching the model to otherdata models. The analysis of large enterprise data models and schemas isoften done by domain experts or consultants, and is very labor-intensiveand costly. Thus, there is room for improvement.

SUMMARY

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

A method for generating a metadata representation of a first databasemodel. The method may be implemented by one or more computing devicescomprising at least one hardware processor and one or more tangiblememories coupled to the at least one hardware processor.

A source representation of the first database model may be received. Thesource representation may include a representation of at least a firstdatabase table including at least a first column, the first databasetable representation including at least a first identifier for the atleast first database table and at least a second identifier for the atleast first column.

A first instance of a metastructure schema object datatype may begenerated based on the first database table representation. Themetastructure schema object datatype may include a first data memberrepresenting an identifier for a database object represented by aninstance of the metastructure schema object datatype and a second datamember representing a database object type associated with the databaseobject. Generating the first instance of the metastructure schema objectdatatype may include assigning the first identifier of the firstdatabase table to the first data member of the first instance.Generating the first instance of the metastructure schema objectdatatype may include determining that the first identifier is associatedwith a database table. Generating the first instance of themetastructure schema object datatype may include assigning a typeidentifier to the second data member of the first instance indicatingthat the first instance represents a database table.

A second instance of the metastructure schema object datatype may begenerated based on the first column representation. Generating thesecond instance of the metastructure schema object datatype may includeassigning the second identifier of the first column to the first datamember of the second instance. Generating the second instance of themetastructure schema object datatype may include determining that thesecond identifier is associated with a column of a database table.Generating the second instance of the metastructure schema objectdatatype may include assigning a type identifier to the second datamember of the second instance indicating that the second instancerepresents a column of a database table.

The first instance of the metastructure schema object datatype and thesecond instance of the metastructure schema object datatype may bestored in association.

A method for maintaining data model mappings is provided herein. A firstdata model may be received. The first data model may include one or morestructural components and one or more relationships between structuralcomponents. A first data schema for the first data model may begenerated. The first data schema may include a set of schema objectscorresponding to the one or more structural components of the first datamodel. A given schema object may include a schema object identifier anda structural component identifier. The first data schema may include aset of relationship objects corresponding to the one or morerelationships in the first data model. A given relationship object mayinclude a relationship object identifier, a first schema objectidentifier, and a second schema object identifier.

A second data model may be received. The second data model may includeone or more second structural components and one or more secondrelationships between second structural components. A second data schemafor the second data model may be generated. The second data schema mayinclude a second set of schema objects corresponding to the one or moresecond structural components of the second data model. A given secondschema object may include a second schema object identifier and a secondstructural component identifier. The second data schema may include asecond set of relationship objects corresponding to the one or moresecond relationships in the second data model. A given secondrelationship object may include a second relationship object identifier,a third schema object identifier, and a fourth schema object identifier.

One or more mappings between the first data model and the second datamodel may be received. A data schema alignment may be generated for thefirst data model and the second data model. The data schema alignmentmay include a set of alignment mappings based on the one or morereceived mappings. A given alignment mapping may include identifiers forone or more schema objects from the first data model and an identifierfor a schema object in the second data model.

A method for generating a metadata representation of a first data modelis provided herein. The method may be implemented by one or morecomputing devices comprising at least one hardware processor and one ormore tangible memories coupled to the at least one hardware processor.

A source representation of the first data model may be received. Thesource representation may include a representation of one or morestructural components of the first data model, respectively havingidentifiers and types. One or more instances of a metastructure schemaobject datatype may be generated based on the one or more structuralcomponents of the source representation. The metastructure schema objectdatatype may include a first data member representing an identifier fora structural component represented by an instance of the metastructureschema object datatype and a second data member representing astructural component type for a structural component represented by aninstance of the metastructure schema object datatype.

Generating a given instance of the metastructure schema object datatypefor a given structural component may include assigning a firstidentifier of the given structural component to the first data member ofthe given instance. Generating a given instance of the metastructureschema object datatype for a given structural component may includedetermining a first type associated with the given structural component.Generating a given instance of the metastructure schema object datatypefor a given structural component may include assigning the first type tothe second data member of the given instance.

The one or more instances of the metastructure schema object datatypemay be stored in association.

The foregoing and other objects, features, and advantages of theinvention will become more apparent from the following detaileddescription, which proceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating various data targets that may be usedwith recursive rules language technologies.

FIG. 2 is a diagram illustrating definition formats for variouscomponents of a data transformation specification.

FIG. 3 is a diagram illustrating various rules, and how rules may berecursively related to one another.

FIG. 4 is a diagram illustrating an example computing architecture inwhich recursive rule language technologies can be implemented.

FIG. 5 illustrates how recursively defined rules can be converted tocombined or nested conditional statements.

FIG. 6 is an example user interface screen for defining a datatransformation specification.

FIG. 7 illustrates how a data transformation specification in a domainspecific language can be converted to an executable specification orformat, such as SQL code as shown.

FIG. 8 is a flowchart of a disclosed method of compiling atransformation specification in a domain specific language to anexecution format.

FIG. 9 is a flowchart of a disclosed method that can be carried out by adomain specific language compiler.

FIG. 10 is a flowchart illustrating operations in a disclosed embodimentof rendering a data transformation specification user interface.

FIG. 11A is a diagram depicting a matching metastructure schema betweendata models.

FIG. 11B is an architecture diagram depicting a system for using andstoring the matching metastructure.

FIG. 12A depicts a matching metastructure definition.

FIG. 12B depicts an example implementation of the matching metastructureas a database schema.

FIG. 12C is a diagram depicting an example matching metastructure fortwo databases.

FIG. 13 depicts version transformation of a matching metastructureschema.

FIG. 14A is a flowchart illustrating a process for data model conversionto a metastructure format or schema.

FIG. 14B is a flowchart illustrating a process for data model mappingconversion to a matching metastructure format or schema.

FIG. 14C is a flowchart illustrating a process for mappingtransformation conversion to a matching metastructure format or schema.

FIG. 15A is a schematic diagram depicting an application environment fora matching metastructure module.

FIG. 15B is a schematic diagram depicting a system environment for amatching metastructure module.

FIG. 15C is a schematic diagram depicting a network environment for amatching metastructure module.

FIG. 16A illustrates a process for generating a metadata representationof a first database model.

FIG. 16B illustrates a process for maintaining data model mappings.

FIG. 16C illustrates a process for generating a metadata representationof a first data model.

FIG. 17 is a diagram of an example computing system in which describedembodiments can be implemented.

FIG. 18 is an example cloud computing environment that can be used inconjunction with the technologies described herein.

DETAILED DESCRIPTION

A variety of examples are provided herein to illustrate the disclosedtechnologies. The technologies from any example can be combined with thetechnologies described in any one or more of the other examples toachieve the scope and spirit of the disclosed technologies as embodiedin the claims, beyond the explicit descriptions provided herein.Further, the components described within the examples herein may becombined or recombined as well, as understood by one skilled in the art,to achieve the scope and spirit of the claims.

Example 1—Data Model Matching Metastructure Overview

Entities often run many different data-driven applications fromdifferent providers. Such disparate applications often have their owndata models, but these different data models may work on the same orsimilar data, at least in part. Even applications from the same providermay have different data models. Where the different data models utilizedifferent data, their systems may need to be integrated together forimproved performance or efficiency across the entity, or to facilitateyet further applications that may use data models of multipleapplications, such as analytic or data visualization applications.Failure to integrate such systems and their data models may create datasilos (e.g. non-integrated data storage), which may have a detrimentaleffect.

For example, data silos may prevent common information from beingbroadly available within the entity, which may limit the ability toeffectively use the data the entity has. Operating two separate datasilos covering the same or similar data may lead to violations of dataintegrity, such as by having different information covering the sametopic because one system (data silo 1) was updated while the othersystem (data silo 2) was not. This can lead to significant performancefailures in the entity, because there is no “true” or “accurate” commonview of the entity's data. Further, procedures that attempt to ensurecompliance with data regulations (such as regarding sensitive orpersonally identifying information) may be difficult to efficiently oraccurately implement across multiple data silos.

Accordingly, avoiding data silos and integrating data may overcome theseissues, such as when multiple data-driven applications are in use. Datamodel matching, such as mapping or aligning a data model with anotherdata model, generally improves data integration across disparatesystems. However, data model matching is generally expensive andlabor-intensive, and can require a detailed understanding of the datamodels.

Additionally, there are many other scenarios where a thoroughunderstanding of a data model is important to effectively or efficientlyaccomplish data integration. For example, when analyzing a new datamodel for acquisition or upgrade, quickly understanding the data modelto determine if it meets basic requirements is important. As anotherexample, ETL (extract, transform, load) processes often migrate or movedata from one database to another database, such as a part of systemupdates, database synchronizing, or data provisioning, and generallyrequires a good understanding of the data models involved. Anotherexample is when configuring an environment to house a database system,which generally requires an understanding of which components in a datamodel are closely related to which other components. In yet anotherexample, a collaboration between different people or businesses may leadto a shared database system, which may require consolidation of datafrom their respective database systems. Or, database system integration,where separate database systems from the different people or businessescommunicate with each other, can require a thorough understanding of thedata models. In all such examples, a thorough and conceptualunderstanding of the databases can facilitate efficient and effectiveuse of the data models or databases. Automating such tasks or analysisof the data models or database schemas may be beneficial, but can bedifficult without a common framework for the data models.

As a more detailed example, an entity may acquire a standard data modelfor use in integrating its current multiple databases (or differentapplications using a common database, but having data stored indifferent schemas), including as part of transitioning to a new orupdated database software. However, the standard data model may becomplex, as well as the multitude of currently operating databases datamodels. For example, database schema for ERP systems often includethousands of tables, where each table can include many different fields.The tables and fields can be interrelated, and the schema can be evenmore complex to analyze given that the tables and fields often do nothave names that are easily understood by humans. The current databasesshould be mapped to the new standard database to integrate the systems,which may require multiple consultants and experts to spend significantamounts of time performing the labor-intensive task of analyzing the newdata model and the multitude of current databases to align them with thenew data model. Further, the consultants and experts may not know whereto start, or how to efficiently document, the data model mapping betweenthe new data model and each of the current databases or schemas. Alightweight and standardized method or format, such as the matchingmetastructure technologies disclosed herein, generally makes mappingdata models much easier and faster, while being less costly and lesslabor-intensive, because consistency in format generally increasesefficiency, such as by allowing re-use of work, and may be automated orsemi-automated.

Continuing the detailed example above relating to potential issues withprior approaches to integrating databases/schemas, the entity may formseveral teams to perform the mapping process between the new data modeland the current databases. However, each team may have a differentapproach to identifying and recording the mappings. For example, thefirst team may be composed of IT experts that plan to write SQLfunctions for mapping the data from a current database to the newdatabase of the new data model. A second team may be composed of ITconsultants that propose using a “well-matured” spreadsheet for trackingthe mappings. A third team may be composed of subject matter expertsthat prefer to simply write basic data mapping statements, such as firstorder logic statements in natural language. A lightweight andstandardized method or format may make integrating each teams' effortseasier and more cost-effective because each team may then generateresults (mappings) that can readily be integrated together.

As another detailed example, a consultant focusing on data integrationprojects may develop templates, such as text documents or spreadsheets,for carrying out data model mapping tasks, such as maintaining ortracking mappings. However, over time the mapping tasks becomeincreasingly difficult and complicated, as source data model structureschange, target data model structures change, and the mappings (with anyassociated transformations) are persisted in permanently extended,corrected, and changed documents. A common format and methodology maygenerally reduce the overhead work in maintaining a large set of mappingdocumentation.

As yet another detailed example, a consultant or data scientist workingon several data model integration projects may seek to analyze the datamodel mappings across many different systems to find patterns that mayimprove the mapping process. However, the data models and mappings mayall be maintained in heterogeneous formats, with little or nostandardization across integration projects. Without a common format ormethod for understanding data models and mappings, such broad analysismay not be possible, or may be prohibitively costly or labor-intensive.A common format and methodology may facilitate such detailed analyses ofdata model mappings across a wide variety of data models and data modelintegration projects.

The matching metastructure technologies disclosed herein provide such acommon or standardized framework for understanding, analyzing,comparing, or mapping data models, and persisting the data models inassociation with their mappings. The matching metastructure may be aversatile or universal definition or format for a data model, or formodelling a data model. The matching metastructure therefore facilitatesintegrating data models by facilitating analysis or comparison betweendisparate data models. Generally, the matching metastructure providesconcisely defined terminology and representation for data models, whichfacilitates automatic analysis and comparison across data models, suchas data model clustering or data model alignment or mapping. Further,the matching metastructure may provide an efficient format for storingand retrieving data models. Additionally, the matching metastructure mayfacilitate efficient and consistent (and thereby, accurate) lifecyclemanagement of data models and associated data model analysis or metadata(e.g. mappings). The matching metastructure is an open, generic formatand methodology, and so is not limited to a particular format or type ofdata model, but is instead versatile in its applicability to andeffectiveness for data models. Further, the matching metastructure is anextensible model, allowing for flexibility in adapting to new datamodels or additional features for representing or analyzing data models.

A data model may be an abstract model which may organize elements ofdata and standardize how they relate to one another and to properties ofreal world entities. A data model may be a conceptual data model,broadly defining elements, or a physical data model, specificallydefining an implementation structure (e.g., definitions of specificdatabase objects, such as database tables or views, in a specificprogramming language or database implementation, including definitionsof relationships between such specific objects). A data model may be aschema, such as a database schema. A data model or schema may berepresented as a graph, as described herein.

Matching metastructure functionality may be provided in data modellingsoftware, database analytics software, database management software, ERPsoftware, or other data model- or database-driven software systems (oras a stand-alone system). Examples of such tools are: SAP FSDP™, SAPFSDM™, SAP PowerDesigner™, SAP Enterprise Architect Designer™, SAPHANA™, S/4HANA™, C/4 HANA™, HANA Native Data Warehouse™, all by SAP SEof Walldorf, Germany.

The present disclosure begins with a description of a recursive ruleslanguage, and how recursive rules may be implemented for transformingdata from one data model to another data model (e.g. databases) based ona data model alignment or mappings, in Examples 2-10. Examples 1 and11-16 describe disclosed technologies that facilitate data modelconversion, analysis, mapping, and persistence in the matchingmetastructure.

Example 2—Recursive Rule Language Overview

As computers become more pervasive, integrating data from, or convertingdata between, different sources can become more complex. For example, itmay be desired to use data from different sources in a commonapplication, but the data may be stored in different formats, or using adifferent schema. Or, it may be desired to migrate data to a new format.Altering data values, or metadata associated with the data values(including a schema used to describe or process the data values) can becumbersome, as it can require technical knowledge in understanding aninitial format and schema of the data, a final, desired format andschema, and how to convert the data from the initial format and schemato the final format and schema.

A user's technical knowledge may determine tools that the user prefersto express how data should be arranged or changed, such as using firstorder logic statements (e.g., non-technical descriptions of the desiredchanges), spreadsheets, or actual code (for example, SQL statements).Having different users describe data transformations in different wayscan create redundant work, and make it harder for the users tocommunicate. If team members leave, it may be difficult for new membersto understand the prior member's work.

Transforming data may also require someone with a detailed understandingof the use or purpose of the data. As an individual with a detailedunderstanding of technical aspects of a data set is often not the sameindividual having a detailed semantic understanding of the data,difficulties can arise in transforming data values or metadata.Accordingly, room for improvement exists.

Often, it will be desired to alter a schema in which data is maintained,or to translate data between schemas. For instance, a user may wish tomigrate to a new computing system or to a new software application froma legacy system or software application. In order to accomplish themigration, it may be necessary to migrate data from a legacy schema to anew schema. Or, it may be desired to use a data set with (or from)multiple software applications, but the software applications may usedifferent data formats or schemas. As an example, a first databasesystem may maintain a particular type of data in an attribute “A” of afirst schema, and a second database system may maintain that type ofdata in an attribute “B” of a second schema. Even if the attributes havethe same name (e.g., both are “A”), the values can be assigned usingdifferent schemas. For example, a first schema may assign values thatrepresent categories as 1, 2, or 3, and a second schema may instead useA, B, or C. In addition, criteria for determining what category isassigned to a particular record may differ between the first schema andthe second schema. The recursive rules language technologies can be usedboth to determine which data targets will be mapped (e.g., which datatargets will be used to define a change to another data target), as wellas what values will be assigned to the data target being modified.

Often, a non-technical user will create logical propositions that definehow data values or metadata elements should be altered, such as usingfirst order logic statements. These logical propositions can then beexpressed in a spreadsheet, typically by more technically sophisticatedusers, but who still may not be users responsible for final programmaticimplementation of a transformation. Eventually, the logicalpropositions, or spreadsheet representation, can be translated to aprogramming language, such as SQL (structured query language), to beimplemented on an actual data set.

However, spreadsheet expressions of the logical propositions can varysignificantly between users, and can be hard to understand, particularlywhen large numbers of propositions or rules exist. In addition, whetherin a spreadsheet representation or in a programming languagerepresentation, it can be difficult to reuse results, or to modify rulesif conditions change. For example, if a SQL implementation of a datatransformation exists, and a particular schema change is added to,removed from, or modified in underlying logical statements, it may benecessary to re-implement the entire SQL code accomplishing atransformation. At the least, determining where/how to modify aprogramming language implementation of a data transformation can becomplex and time consuming.

Such technologies provide a language (which can be referred to asRecursive Rule Language, or RRL) where first order logic statements canbe defined and translated into a variety of implementable formats.Typically, the language is not a programming language, or otherwise doesnot specify operations that can be directly executed by a processor orparticular software application. Such languages can be referred to asdomain specific languages.

The logic statements can be simple to understand, reusable, and easy tomodify. The logic statements can also refer to one another, in a sensebeing recursive. Accordingly, some or all of a data transformation canbe implemented using an automated framework, where first order logicstatements can be compiled into commands for a specific executionenvironment. Even if some aspects of a data transformation cannot, atleast initially, be automatically implemented, the cost and time ofaccomplishing a data transformation, as well as the involvement ofprogrammers or software developers, can be greatly reduced.

Such recursive rule language technologies provide a language fordescribing first order logic statements, which can be used to defineconditions, or rules. The rules can define statements that can be testedfor truth or falseness. The rules can include a building block, anoperator, and another building block, where the building blocks serve asoperands for the operator. Building blocks can be, for example, datatargets, a value (e.g., a literal of a datatype, such as a particularvalue of a float, string, etc., including Boolean values such as TRUE orFALSE), or another rule. A data target can refer to a data structurethat can be read from or written to, such as a logical pointer to aparticular storage (e.g., memory or secondary storage) location orstructure. The data target may have a label or identifier, such as thename of a column/attribute of a relational database table. In aparticular example, the data target can be referenced by a URI for aparticular data structure (e.g., the name or identifier of the datastructure can in turn be mapped to a URI or logical pointer to the datastructure, such as to an information schema or data dictionary).Locations (e.g., locations of specific data values or elements of a datatarget) can also be specified with respect to a particular datastructure, such as a particular node of hierarchically arranged dataelements (e.g., a graph, heap, or tree), or a particular index positionof an array, queue, list, etc.

Actions can be defined, where an action can represent a specific valuethat is assigned to a data target when a particular rule evaluates toTRUE. For example, if a particular attribute has a particular name oridentifier, the name or attribute can be changed to another value.Actions can be aggregated in a rule set or mapping, where a mappingincludes a plurality of actions that are sequentially evaluated in aparticular, specified order until an action of the mapping (e.g., a ruleassociated with a particular action) evaluates to true. When an actionis determined to be executable, the process of evaluating actions in agiven mapping for a given analysis (e.g., a particular application of arule to a particular instance of rule building blocks) terminates.

In practice, a user can define data targets, rules, actions, andmappings in a language (or notation) that is programming-languageindependent. The rules, actions, and mappings can be expressed, however,using particular tokens, syntax, and semantics, so that the rules,actions, and mappings are expressed in a standardized manner. Thestandardized rules, actions, and mappings can then be automaticallyconverted to a particular programming language or other executableformat that can then be executed on one or more data sources. As anexample, rules, actions, and mappings can be analyzed and automaticallyconverted to one or more SQL statements (such as in a particular SQLdialect—for a particular database system) that can be executed on one ormore database systems. Or, the elements of the transformationspecification can be converted to scripted commands to cause a softwareapplication to perform a transformation.

If a user decides to add, modify, or remove particular rules, actions,or mappings, updated executable instructions can be automaticallygenerated without the need to involve programmers or softwaredevelopers. Because the elements of the transformation specification inthe domain specific language are independent of a particular executionformat, the rules, actions, and mappings can be more easily reused. Forexample, a variety of actions can be defined that use a particular rulewithout having to rewrite the rule. Similarly, various mappings can becreated that include a particular action, without having to rewrite theaction. In addition to being easy to reuse, the use of the programminglanguage independent representation of first order logic statements, andother actions using such statements, can be easy to understand,including transformation specification elements that includerelationships between multiple elements (e.g., recursively arrangedrules, where a given rule references one or more additional rules, whichin turn may reference one or more additional rules).

The ease of defining and implementing rules, actions, and mappings canalso facilitate debugging efforts. For example, logic statements andother components can be checked for syntactic correctness as thestatements are being developed, or otherwise prior to, or during,compilation to a particular executable format. Similarly, the ability toautomatically generate executable code or commands can facilitatedebugging efforts while rules are being developed, rather than having towait until rules and other components for an entire data transformationspecification have been implemented in a computer-executable format.

Example 3—Example Data Targets and Elements Thereof

FIG. 1 provides examples of data targets that can be used with thedisclosed recursive rule language technologies. As discussed in Example1, a data target can be a particular data structure that is capable ofstoring a plurality of data elements, typically of a particular datatype. The data structure typically can be read from, written to, orboth, and typically has metadata, such as a name or identifier that canbe used to refer to or access the data structure, and optionallylocation information (e.g., a logical pointer) that can be used toaccess the data structure. In some cases, the location information canbe explicit (e.g., a metadata field can store the location information),while in other cases the location information can be implicit (e.g., thedata structure is in memory and a processor “knows” a memory location atwhich the data structure can be accessed based on the name or identifierof the data structure).

In some cases, a data structure can be “read only,” such as when avalue, for example an identifier, associated with a first data target(e.g., a name of the data structure, or a particular data element of thedata structure) is used to determine whether and how a value should bechanged for, or assigned to, a second data target. For example, theidentifier of an attribute A might be accessed to determine that anattribute B should be changed to attribute C, but the identifier ofattribute A may not be altered. Data targets referenced in actionstypically are capable of both being read from and written to using therecursive rule language technologies. That is, if a data targetcorresponds to an attribute A of a database table, the identifier ofattribute A, and optionally particular values held in the data structureof attribute A, can be read by a disclosed technology, and theidentifier of the data structure can also be changed (e.g., changed fromA to B). However, it is possible that some data targets need not be readby the recursive rule language technologies, but only written to.

FIG. 1 illustrates data targets in the form of components of relationaldatabase tables 108, 110. The tables 108, 110 can have rows or records114 and columns or attributes 118. Each row 114 can be associated withan identifier 122, and can provide values for one or more (includingall) of the attributes 118 for a given table. An attribute 118 can beassociated with a particular datatype, such as a primitive datatype(e.g., integer, float, string, VARCHAR, or date).

The attributes 118 can correspond to particular data targets. A definedrule can analyze the identifier of the attribute, and optionally, valuesof particular data elements of the particular data target, to determinewhether rule conditions are satisfied. Similarly, if the data target isdefined with respect to an action, the action can determine what valueis written for the data target and, in some cases, particular dataelements of the data target type.

Particular data elements, such as a data element at a particularrow/column location of a tables 108, 110 can be accessed in variousmanners, such as by identifying a record by its identifier 122 and thename of a particular attribute 118. That is, the identifier 122 canserve as a primary key for a given row 114. In other cases, one or moreattributes 118 can serve as a primary key for a row 114. A table 108,110 may have more than one attribute or combination of attributes thatcan serve to uniquely identify a given row 114 (e.g., a table may have aprimary key and multiple other super keys).

Data elements of a data target, such as the tables 108, 110, can bereferenced in other ways, such as using logical pointers to discreteattributes 118 or row/column locations, or using URIs to access aparticular table attribute or value. For example, a table 108, 110 canbe represented as a two-dimensional array, and particular indexpositions can be used to access particular rows, particular columns, orparticular row/column locations.

FIG. 1 also illustrates data targets in the form of an instance of anabstract data type 130. The abstract data type instance 130 can have anidentifier (e.g., a “name” of a variable, or instance, of the datatype)134, optionally one or more methods 138, and one or more data members142 (shown as data members 142 a, 142 b), each of which can beassociated with an identifier 146, and can correspond to a data target.The identifiers 146 can be used to refer to the corresponding datatarget. All or a portion of the data members 142, such as data members142 a, can be mapped to values in another data target, such asrow/column locations of a table 108, 110. Other data members 142 b canhave data targets that are defined in the instance 130, not withreference to another data target or other data source. The data members142 can be accessed by referencing the instance identifier 134 and therelevant data member identifier 146.

A tree 160 is provided as another example of a data target formed from acollection of data elements. The tree 160 includes a plurality ofhierarchically arranged nodes 164. Each node 164 can have a nodeidentifier 168 and can store at least one value 172. In at least somecases, the value 172 of a node 164 for read or write purposes can beaccessed by specifying the node identifier 168. In other cases, theappropriate node 164 can be located in another manner, such as byspecifying a current value 172 of the node. That is, the tree 160 can bedefined in such a way that a given value 172 can be located by suitablytraversing the tree. Similar considerations can apply for reading orwriting values in another type of data structures (e.g., stacks, queues,lists, heaps, or graphs).

Typically, particular data targets (e.g., the attributes 118 or datamember identifiers 146) can be analyzed to determine whether they meetparticular criteria, such as having a particular value that satisfiesone or more rules (e.g., having an attribute or data member name thatmatches the rule criteria). In some cases, particular data elements of adata target can be analyzed to determine whether they meet the rulecriteria (e.g., if rows of a table have attribute values that satisfythe criteria). If the particular criteria are met, a value associatedwith another specific data target type can be modified (e.g., if anattribute has a specified value, another attribute, which can be for adata target instance being analyzed, can be assigned a particular value,such as values for a first attribute being analyzed and used to assignvalues of A or B to a second attribute, depending on the values). As anexample, in SQL, a rule can be defined to select data values meetingfirst criteria for a first data target identifier and to map the valuesto a new identifier.

Example 4—Example Elements of a Data Transformation Specification

FIG. 2 illustrates examples of how data targets, rules, actions, andrule sets (or mappings) can be defined in a particular programminglanguage-independent representation, such as a domain specific language.Data target definitions 208 can include a data target identifier 210 anda location identifier 212. The data target location identifier 212 canbe information sufficient to access (e.g., read, write, or both read andwrite access) a value associated with the data target, such as anidentifier for the data target in a schema, and which in at least somecases can also be used for reading values associated with instances ofthe data target or writing a value for instances of the data target.That is, the data target location identifier 212 can serve as a logicalpointer to values (including metadata values) associated with the datatarget identifier 210. In particular examples, the data target locationidentifier 212 can be a URI or a file path, such as to a schema or datadictionary definition of the data target (e.g., a path to the name ofthe data target in an information schema or a data dictionary).

In some cases, the data target location identifier 212 can be omitted,at least for purposes of defining a data transformation specification.For example, a data target can be created that will hold a valueassigned by a particular action (as described herein). The data targetcan later be mapped to a data target location identifier 212, such as alocation identifier for a particular schema element, such as anattribute name in a database schema.

Language elements can be provided to declare data targets. For example,the following statement declares data target “OBJ_1” and data target“OBJ_2”:

DATA OBJECT DEFINITION: OBJ_1, OBJ_2

The above definition defines two data objects (or data targets) whichcan later be tested for particular values using rules, as describedbelow. OBJ_1 and OBJ_2 can be used to refer to particular attributes ofone or more tables of a relational database system, in a particularimplementation. That is, a table may have an attribute with the name“OBJ_1.”

Rule definitions 216 can include a rule identifier 218 that can be usedto access or identify a given rule. Each rule can have the form<building block> <operator> <building block>, in a particularimplementation. As shown in FIG. 2, an implementation of this format isshown as each rule identifier 218 being associated with a first buildingblock ID 220, an operator 222, and a second building block ID 224. Abuilding block, such as building blocks 220, 224, can be selected from adata target, a literal (e.g., a particular value of a particulardatatype, including Boolean values), or another rule. Operators caninclude, for example, operators such as equality, greater than, lessthan, greater than or equal to, less than or equal to, OR (logical or),AND (logical and), or XOR. Operators may also be negated (e.g., NOT, !),in particular implementations. According to an example rule definitionsyntax, example rule definitions include:

RULE DEFINITION rule_1: OBJ_1=‘Category A’

RULE DEFINITION rule_2: OBJ_2>5.5

RULE DEFINITION rule_3: rule_1 AND rule_2

When the above rules are executed, particular schema elements, andvalues associated therewith, can be tested for rule compliance. Forexample, OBJ_1 and OBJ_2 can be particular database columns, and valuesin these columns can be evaluated to determine if the rules aresatisfied for such values. From the above examples, it can be seen thatrules can be recursive, in that a given rule can be defined withreference to other rules.

Action (or consequence) definitions 230 can include an action identifier232 that can be used to access or identify a given action. Each actioncan have the form <rule> <data target> <operator> <value>, shown in FIG.2 respectively as 234, 236, 238, 240. The operator 238 is typically theassignment operator. According to an example action definition syntax,an example action definition is:

CONSQUENCE DEFINITION consequent_1: rule_1→OBJ_2=‘CAT_A’

The above definition means that when the value of a row for OBJ_1 is“Category A” the corresponding instance for OBJ_2 will be given a valueof “CAT_A,” thus allowing the instance to be converted from a firstschema to a second schema.

Actions can be evaluated individually, or as sets. Action set, ormapping, definitions 246 can include a mapping identifier 248 that canbe used to access or identify a particular mapping. As shown in FIG. 2,an action set includes a plurality of action identifiers 250, 252, 254.An action set typically applies an order to the included actionidentifiers 250, 252, 254. The action identifiers 250, 252, 254 aresequentially evaluated until the conditions of a particular action aresatisfied, or all action identifiers for the rule set have beenevaluated, and none were found to be satisfied. Normally, once theconditions for a particular action 250, 252, 254 are satisfied, theaction is executed, and further evaluation of the rule set isdiscontinued, at least for a particular instance being evaluated. Anexample action set definition format can be <action> <action> <action>,with a specific example being:

MAPPING DEFINITION mapping_1: action_1, action_2

In the above definition, action 1 will first be evaluated. If the rulefor action 1 is satisfied, the consequence for action 1 will beexecuted, and action 2 will not be evaluated for the instance beingevaluated. If the rule for action 1 is not satisfied for a giveninstance, the rule for action 2 will be evaluated.

Example 5—Example Rule Recursion

FIG. 3 illustrates how rules can reference other rules, thus providing arecursive relationship between rules. FIG. 3 illustrates a plurality ofrules 310 (rules 310 a-310 h as shown). Rules 310 a, 310 b, 310 c are“independent,” in that they do not themselves reference another rule.However, each of the rules 310 a, 310 b, 310 c are referenced by one ormore of recursively defined rules 310 d, 310 e, 310 f, 310 g, 310 h.Rules 310 d-310 h are recursive in the sense that determination of theresult for a given rule requires evaluation of one or more additionalrules that are referenced by the given rule.

Rules 310 e and 310 h are both defined with reference to two otherrules, and evaluate to true if both referenced rules evaluate to true,as indicated by the AND operators 314. Rule 310 f is also defined withrespect to two other rules, but evaluates to true if the firstreferenced rule evaluates to true and the second referenced ruleevaluates to false, as indicated by the NOT operator 316.

Note that rule 310 h involves two levels of recursion, as rule 310 hreferences rule 310 g, which in turn references rule 310 a. Similarly,rule 310 f references rule 310 e, which in turn references rules 310 aand 310 b. Note also that a rule, such as rule 310 a, can be referencedby multiple rules, such as being directly referenced by rules 310 g and310 e, and indirectly referenced by rules 310 h and 310 f. Although notshown in FIG. 3, a given rule need not have a recursive relationshipwith any other rule—neither being referenced by another rule orreferencing another rule.

FIG. 3 illustrates several important advantages of the recursive rulelanguage technologies. For example, FIG. 3 illustrates how a given rule,such as rule 310 a, can be reused in conjunction with multiple otherrules. Although not shown in FIG. 3, another way that rules, such asrule 310 a, can be reused is by incorporating a given rule into multipleactions, where an action in turn can be incorporated into multipleaction sets.

Example 6—Example Implementation Architecture

FIG. 4 illustrates an example architecture 400 in which the recursiverule language technologies can be implemented. The architecture 400generally includes a transformation specification 410, a transformationengine 414, one or more executable transformations 416 (shown astransformations 416 a-416 c), and one or more data stores (also referredto as data sources) 418 (shown as 418 a-418 c). The transformationspecification 410 includes information sufficient to define atransformation in a programming-language independent representation,such as a domain specific language having the syntax shown in FIG. 2.The transformation specification 410 can be defined in a file, datastructure, abstract data type, serialized format (e.g., JSON or XML), orother suitable representation. In some cases, the transformationspecification 410 directly includes relevant transformation elements,such as rule definitions, action definitions, and the like. In othercases, the transformation specification 410 can define transformationelements (e.g., rules, actions) that are maintained or definedelsewhere, optionally included in one or more of the data stores 418. Asan example, transformation specification 410 can include a fulldefinition of a Rule X, or can indicate using an identifier that Rule Xis used by the transformation, where the definition of Rule X can thenbe accessed by, or made available to, the transformation engine 414.

In some cases, the transformation specification 410 includes definitionsof, or references to, data targets 420, rules 422, actions 424, mappings426, or combinations thereof. Particularly when definitions of elementsof a transformation specification 410 are not provided in thetransformation specification itself, the transformation specificationcan include fewer elements. For example, it may be sufficient to includeidentifiers for actions 424 or mappings 426 that are used in thetransformation specification 410. When the actions 424 or mappings 426are accessed, the underlying rules, data targets, and, in the case ofmappings, actions, can be determined and accessed (e.g., if an action Xis defined with respect to rule Y, the transformation specification 410can include a reference to action X, and when the definition of action Xis accessed, it can be determined that the definition of rule Y shouldalso be accessed in order to fully process action X).

The transformation engine 414 can include a parser 440, a constraintchecker 444, a rule expander 448, and a compiler module 452. The parser440 can process a transformation specification 410 to determine datatargets 420, rules 422, actions 424, and mappings 426 included in thetransformation specification. In the event references to elements of atransformation specification 410 are included rather than a fulldefinition, the parser 440 (or another component, including a componentnot shown in FIG. 4) can retrieve full definitions for use in generatingthe executable transformations 416.

The constraint checker 444 can analyze components of the transformationspecification 410, as provided by the parser 440, to determine whetherthe components comply with various constraints. One constraint can besyntactic correctness. Another constraint can be that components of thetransformation specification 410 do not refer to components that are notincluded in the transformation. For instance, a constraint violation canbe indicated if a mapping includes Action 1, Action 2, and Action 3, andAction 2 is not included in the transformation specification. Anotherconstraint can be correct operator usage, such as making sure that alogical expression (e.g., AND) includes expressions on both sides of theoperator. In some cases, the constraint checker 444 can perform morecomplex constraint checking, such as making sure a referenced datatarget exists on a data source 418, or confirming that data typesassociated with elements of the transformation specification 410 are thesame or at least compatible (e.g. a comparison between an integer and afloat may be allowed, as the types are compatible, but a comparisonbetween an integer and a string may generate a constraint violation).

The rule expander 448 can generate statements that can be converted bythe compiler module 452 to an executable transformation 416. FIG. 5illustrates an example of how a rule, rule_3, can be defined in terms ofother rules, rule_1 and rule_2. The initial version of rule_3 does notindependently contain enough information for rule_3 to be compiled intoan executable format. The rule expander 448 can incorporate thedefinitions of rule_1 and rule_2 into a revised version 510 of rule_3,which directly includes the definitions of rule_1 and rule_2, and thuscan be compiled into an executable format. In some cases, the ruleexpander 448 combines conditional statements associated rules having arecursive relationship into a nested manner, as shown in the revisedversion 520 of rule_3. The nested conditional statements can then becompiled into a particular executable format.

Although the rule expander 448 may be needed to convert at least somerules (e.g., rules that recursively reference other rules) into a formthat can be compiled into an executable format, the conversion can becarried out automatically, rather than requiring manual conversion(e.g., manual code writing) by a programmer or software developer, orbeing required to be entered initially in a non-recursive manner (e.g.,in the form 510 or 520). Thus, the rule expander 448 can facilitate theuse of relatively simple rules (e.g., first order logic statements) asbuilding blocks for complex rules, which in turn facilitates rulere-use, ease of understanding of rules and their interrelationships,debugging, and rule creation.

Returning to FIG. 4, the compiler module 452 can include one or morecompiler engines 456. The compiler engines 456 are configured to convertelements of the transformation specification 410, including as processedby the parser 440, constraint checker 444, and rule expander 448, to anexecutable format 416 that can be executed by one or more of the datasources 418. Although shown as separate, multiple, including all,compiler engines 456 can be implemented in a single component, havingroutines for converting from a programming language independent formatto a given executable format, which can be in a programming language ora collection of instructions that can be implemented by one of the datasources 418.

As an example of how a programming language—(or other executableinstruction—) independent representation of the transformationspecification 410 can be converted to one or more of the executableformats 416, which can then be executed on respective data sources 418,consider a scenario that includes a data source 418 a, in the form of adatabase using a first query language (e.g., a particular dialect of SQLthat may be used with database software provided by a particularvendor), a data source 418 b, in the form of a database using a secondquery language (e.g., a dialect of SQL that is different than thedialect used by the data source 418 a), and a data source 418 c that isconfigured to receive requests for database operations (e.g., queries)using REST protocols, such as the OData protocol. The data source 418 ccan include a handler 460 that processes REST requests, which are thenexecuted against a database system 464.

The transformation engine 414 can select the appropriate compiler engine456 to produce a suitable executable transformation 416 that can beexecuted against a selected data source 418. That is, a user can selecta particular data source 418, and the transformation engine 414 canconvert the transformation specification 410 into an executabletransformation 416 a in the first SQL dialect, used by the data source418 a, an executable transformation 416 b in the second SQL dialect,used by the data source 418 b, into REST requests/API calls 416 c to beprocessed by the data source 418 c, or to multiple of these formats. Inother cases, a user can select one or more formats for executabletransformations 416 without having the corresponding executabletransformation be sent to a data source 418 for execution (e.g., theexecutable transformation can be stored).

Example 7—Example Transformation Specification Definition User Interface

FIG. 6 is an example user interface screen 600 where a user can entercomponents of a data transformation specification in a programminglanguage independent manner, as well as configure execution options. Thescreen 600 can provide a rule definition panel 602 that includes atemplate 604 for defining rules, such as having a field 606 where a usercan enter an identifier for a rule being created, or can select an icon608 to browse for a rule. That is, rules can be defined and stored forreuse, and the icon 608 can allow a user to select a rule repository andbrowse for rules. If the user selects a rule using the icon 608, ruleelements can be populated in the screen 600. In some cases, the user maybe allowed to modify populated rule elements.

The template can include a field 610 where a user can specify a firstoperand, or building block. As with the rule identifier field 606, thefirst operand field 610 can include an icon 612 that a user can selectto browse for previously defined or specified operands. In someimplementations, instead of, or in addition to, providing an icon 608,612 that a user can select to browse for elements, representations ofavailable elements can be provided on the screen 600, and a user maybuild rules by dragging and dropping elements into the appropriatelocation on the template 604. Similar functionality can be provided forother templates depicted in FIG. 6, which templates are furtherdescribed below.

A user can enter an operator into an operator field 614, which caninclude an icon 616 which can be selected to choose from a list ofavailable operators. For example, a window of available operators may bedisplayed when the icon 616 is selected, and the user can select one ofthe displayed operators. A second building block can be specified inoperand field 618, including by selecting from available building blocksusing icon 620. A user can select to add additional rules by selectinguser interface element 622.

The screen 600 can include an action definition panel 628 that includesa template 630 for defining actions. The template 630 can include afield 632 where a user can enter an identifier for an action beingcreated, or can select an icon 634 to browse for actions, which can becarried out at least generally as described for the rule template 604.In at least some examples, a user can select a user interface element636 to indicate that the action is satisfied if a rule entered in a rulefield 640 evaluates to true, or a user interface element 638 to indicatethat the action is satisfied if a rule entered in the rule fieldevaluates to false.

The action template 630 includes elements that allow a user to specifyactions that should be taken if the action conditions are met. A usercan enter an identifier for a data target in field 644, or browse fordata targets by selecting an icon 646. A user can enter an operator infield 648, or browse for an operator by selecting a user interfaceelement 650, in a similar manner as for the operator field 614. A valuecan be entered in a field 652. As has been described, typically theoperator for the operator field 648 is the assignment operator.Accordingly, in at least some cases, the operator field 648 and icon 650can be omitted. If the conditions for the given action are satisfied fora given data instance, the value in the field 652 is assigned to theinstance for the data target entered in the field 644. A user can selectto create additional actions by selecting icon 654.

The screen 600 can provide a mapping definition panel 660 that includesa template 662 for defining mappings, or action sets. The template 662can allow a user to enter actions for the mapping in fields 664, or tobrowse for actions by selecting an icon 666. Additional fields 664 canbe added to a given mapping template 662 by selecting a user interfaceelement 668. An identifier for the mapping can be specified in a field670, or a user can browse for mappings by selecting an icon 672.Additional mappings can be created by selecting an icon 674.

A user can select to take various actions using information entered inthe panels 602, 628, 660. For example, a user can select a consistencycheck user interface element 676, which can analyze the enteredinformation to determine whether it is consistent, such as describedwith respect to the constraint checker 444 of FIG. 4. For example,selecting the consistency check user interface element 676 can run acheck to determine whether all actions specified for a mapping in thepanel 660 reference actions that exist in the panel 628 (or in anotherrepository, at least in some examples). Similarly, selecting the userinterface element 676 can run a check to determine whether all rules anddata targets specified for an action 628 exist in the panel 602, oranother repository. In the event inconsistencies exist, a user can beprovided with a visual indication of the problem (e.g., “mapping X,action Z does not exist”).

A user can select to test transformation information entered in thescreen 600 by selecting a test execute icon 678. In some cases,selection of the test execute icon 678 causes results to be generatedusing a data set to which the rules are applied, but does not change theunderlying data set. If the user wishes to implement a particular set oftransformation operations, the user can select an implement userinterface element 680, which can cause the transformation entered in thescreen 600 to be executed against a specified data source, and theunderlying data is modified according to the specified operations.

A user can select other options, such as an output format, which can bespecified in a field 682, or selected from available options byselecting icon 684. The output format can determine what programminglanguage or execution instruction type, such as SQL, the transformationoperations will be converted to (e.g., specifying a particular compilerengine 456 of FIG. 4 to be used). Similarly, the user can specify aparticular data source to which a transformation specification will beapplied in field 686, or can select from available data sources byselecting icon 688.

As described above, transformation elements, or entire transformationspecifications, can optionally be saved to, or loaded from, arepository. A user can select to save a transformation specificationentered via the screen 600 using a save icon 690, or to load atransformation specification using a load icon 692.

Example 8—Example Executable Format Generation From Domain SpecificLanguage Definition of Transformation Specification

FIG. 7 provides an example transformation specification 710 andresulting SQL code 712 that can be produced using the recursive rulelanguage technologies. The transformation specification 710 includesfour data targets 714, OBJ_1-OBJ-4. The data targets can correspond tofields of one (or more) relational database tables. Rule definitions 716specify particular values of the fields (or attributes) that will resultin the rule evaluating to TRUE. Rule definition 716 a (rule_3) isrecursive, and evaluates to TRUE when two of the rules 716 (rule_1 ANDrule_2) both evaluate to true.

The transformation specification 710 includes two actions, orconsequences, 722 (shown as 722 a, 722 b), which specify values thatwill be assigned to OBJ_4 when particular rules are satisfied. A mapping726 specifies that both actions 722 are to be evaluated, and that action722 a is to be evaluated before action 722 b. As described, if the rule716 a for action 722 a evaluates to TRUE, the corresponding consequence(e.g., assignment) is carried out, and action 722 b is not evaluated. Ifthe rule 716 a is not satisfied, the consequence of action 722 a is notcarried out, and action 722 b is evaluated.

The SQL code 712 is a nested query that includes a main SELECT statement730 that selects results of one of inner SELECT statement 734 and innerSELECT statement 738. Statement 742 indicates that results of only oneof statement 734 or 738 will be returned by the main SELECT statement730. Inner SELECT statements 734, 738 operate similarly to a CASEstatement (e.g., in C, C++), or a series of conditional statements,where the first conditional statement that is satisfied is executed, andthen further evaluation of the conditional statements ceases.

Example 9—Example Data Target Generation

In some cases, a disclosed domain specific language, that is not aprogramming language, may not be powerful enough to accomplish aparticular data transformation. For example, a transformation mayrequire operations such as calculations, join operations (e.g., in arelational database system), groupings, aggregation operations, etc.However, a new data target can be created where the desired operationshave been applied. For example, a more technical user can create adatabase view, and the database view (such as a particular field of thedatabase view) can serve as the data target for the domain specificlanguage. Thus, while often the vast majority of transformationoperations can be natively accomplished using the disclosed domainspecific language, such as on a “base” database system, operations thatcannot natively be accomplished can still be carried out using thedomain specific language, once a suitable data target has been created.Although some intervention by a technical use may be required, theoverall process for conducting a data transformation can still begreatly simplified compared with a scenario where the disclosed domainspecific language is not used.

Example 10—Example Data Transformation Operations

FIG. 8 is a flowchart of an example method 800 of compiling atransformation specification in a domain specific language to anexecution format. The method 800 can be implemented in the computingarchitecture 400 of FIG. 4. At 810, user input is received defining atleast a first rule. The at least a first rule is of a rule format. Therule format includes a first building block, an operator, and a secondbuilding block. The first and second building blocks serve as operandsfor the first operator, and are selected from rules having the ruleformat, a data target, or a literal of a data type.

User input is received at 820 defining at least one action. The at leastone action is of an action format. The action format includes a ruleserving as a predicate for the at least one action, a second operator tobe executed if the predicate is satisfied, a data target serving as afirst operand for the second operator, and a value serving as a secondoperand for the second operator. At 830, a transformation specificationis instantiated that includes the at least a first rule and the at leastone action. An execution format to which the transformationspecification is to be converted is determined at 840. At 850, thetransformation specification is compiled to the execution format.

FIG. 9 is a flowchart of a method 900 that can be performed by domainspecific language compiler. The method 900 can be carried out in thecomputing environment 400 of FIG. 4. At 910, a data transformationspecification in a domain specific language is retrieved. The datatransformation specification is parsed at 920 to determine at least afirst rule and at least a second rule specified in the datatransformation specification. The data transformation specification isparsed at 930 to determine at least a first action specified in the datatransformation specification. At 940, it is determined that the at leasta second rule references the at least a first rule. Nested conditionalstatements are generated at 950, representing conditions of the at leasta first rule and the at least a second rule. An execution format isdetermined at 960. At 970, the nested conditional statements arecompiled to the execution format.

FIG. 10 is a flowchart of a method 1000 for rendering a datatransformation specification user interface useable to define a datatransformation specification in a domain specific language. At 1010, arule definition template is displayed. The rule definition templateincludes a user interface element for a first building block, a userinterface element for an operator, and a user interface element for asecond building block. An action definition template is displayed at1020. The action definition template includes a user interface elementfor a rule and a user interface element for a value. At 1030, user inputis received for the rule definition template and the action definitiontemplate, defining at least one rule and at least one action. A datatransformation specification in a domain specific language is generatedat 1040, and includes the at least one rule and the at least one action.

Example 11—Matching Metastructure System Architecture

FIG. 11A is a diagram 1100 depicting a matching metastructure betweenvarious types of data models. The matching metastructure 1102 may beused to represent a wide variety of types of data models 1104, 1106,1108, 1110, 1112, 1114. For example, the matching metastructure may beused to describe or represent a web interface 1104, an applicationprogram interface (API) 1106, an ontology or ontological description ofa domain 1108, object-oriented classes 1110, a database structure 1112,or a schema (e.g. for a database, or as an entity-relationship diagram)1114. The matching metastructure 1102 may describe or represent othertypes of data models as well. Generally, any type of data model may berepresented by the matching metastructure 1102 because of the specificstructure of the matching metastructure, as described in detail in FIG.12A.

The matching metastructure 1102 may also include mappings betweendifferent data models. In such cases, the data models may be of the sametype, for example, from a database schema 1112 (1114) to anotherdatabase schema 1112 (or 1114). In other such cases, the data models maybe of different types, for example, from an API 1106 to a set ofobject-oriented classes 1110. Because the matching metastructure 1102 isa versatile format for representing data models, data models ofdifferent types may be mapped, compared, or otherwise integrated usingthe matching metastructure. The matching metastructure may facilitatethe schema alignment technologies disclosed in SCHEMA ALIGNMENT ANDSTRUCTURAL DATA MAPPING OF DATABASE OBJECTS patent application filedconcurrently herewith, having inventors Sandra Bracholdt, Volker Saggau,and Jan Portisch, and incorporated herein by reference.

FIG. 11B is an architecture diagram depicting a system 1120 for usingand storing the matching metastructure 1102.

A matching metastructure system 1124 may provide functionality forconverting a data model into the matching metastructure 1102. In someembodiments, the matching metastructure system 1124 may also convertmapping data between two data models into the matching metastructure1102 as well. Additionally or alternative, the matching metastructuresystem 1124 may access a data model alignment or mapping system formapping two data models and receive the mapping results for storagewithin a matching metastructure data storage 1132. The matchingmetastructure system 1124 may perform full lifecycle operations andmaintenance on matching metastructure data, such as the versioning asdescribed herein. The matching metastructure system 1124 may have a fileimport service 1126, an application import service 1128, or a databaseimport service 1130, or a combination thereof. The matchingmetastructure system 1124 may be a stand-alone system or softwareprogram, or may be a matching metastructure module as described herein.

The file import service 1126 may be an exposed interface for receivingor obtaining a data model file 1134 storing a description of a datamodel (e.g. data model schema, graph representation, UML file, etc.).The file import service 1126 may accept the data model file 1134 andconvert it appropriately for use by the matching metastructure system1124, such as to convert the data model file 1134 into the matchingmetastructure or to persist the data model file 1134 in themetastructure data storage 1132, such as after the data model file isconverted to the matching metastructure or if the data model file isalready in the matching metastructure format. In some embodiments, thefile import service 1126 may allow multiple data model files 1134 to beuploaded to the matching metastructure system 1124 in batch, orsimultaneously.

The application import service 1128 may be an exposed interface forcommunicating with a data modelling system 1136. The application importservice 1128 may receive a data model from the data modelling system1136 for conversion to the matching metastructure or persistence in thematching metastructure data storage 1132, such as for persisting afterthe data model received from the data modelling system is converted tothe matching metastructure, or for persisting if the received data modelis already in the matching metastructure format. The application importservice 1128 may request a data model from a data modelling system 1136.In other embodiments, the application import service 1128 may receive adata model from a communication initiated by the data modelling system1136. The matching metastructure system 1124 may have multipleapplication import services 1128 for communication with different datamodelling systems 1136. In other embodiments, the application importservice 1128 may have one or more adapters or plug-ins for communicationwith different data modelling systems or services 1136. Examples of adata modelling system 1136 are SAP PowerDesigner™ and SAPArchitectDesigner™, both of SAP SE of Walldorf, Germany.

The database import service 1130 may be an exposed interface foraccessing a source database 1138. The database import service 1130 mayreceive a data model from the source database 1138 for conversion to thematching metastructure or persistence in the matching metastructure datastorage 1132, such as after the data model received from the sourcedatabase is converted to the matching metastructure or if the receiveddata model is already in the matching metastructure format. The databaseimport service 1130 may request a data model from a source database1138. A source database may store a data model, such as a databaseschema, in a data dictionary or other configuration table or tables,which may be accessed by or provided to the matching metastructuresystem 1124 through the database import service 1130. The databaseimport service 1130 may have access to database connection informationand database credentials, which it may use to query (e.g. via SQL) asource database 1138 for a database schema representing the data modelof the source database. In some embodiments, the database import service1130 may have one or more adapters or plug-ins for accessing differentsource databases.

The matching metastructure system 1124 may access the metastructure datastorage 1132 to store metastructure descriptions of data models andalignment data for mapping between data models. The metastructure datastorage 1132 may be a database implementing a schema of the matchingmetastructure as described herein.

The matching metastructure system 1124 may be implemented as amultitenant system with the metastructure data storage 1132 as amultitenant database. In such an embodiment, the metastructure datastorage 1132 may be a single database, such as a distributed database,housing metastructure data for multiple tenants. In such embodiments, atenant may only be able to access their metastructure data, but smartservices may be able to collect or analyze data across tenants, such asfor analyzing data model alignments or mappings. For example, forcommon, standard, or non-proprietary data models, the matchingmetastructure definition for the non-proprietary data model may beavailable between multiple tenants, thus allowing the metastructuresystem 1124 to avoid re-creating commonly used data models in thematching metastructure.

The matching metastructure system 1124 may have a user interface/API1122. The user interface 1122 may provide a user with a display of datamodels stored in the matching metastructure system 1124. The userinterface/API 1122 may allow a user to select a source 1134, 1136, 1138for obtaining a data model for conversion or storage in the matchingmetastructure system 1124. The user interface/API 1122 may allow a userto configure a set of options for converting or storing data models inthe matching metastructure system 1124. The user interface/API 1122 mayallow another program or process to access the matching metastructurefunctionality of the matching metastructure system 1124, such as toobtain a matching metastructure representation of a data model (e.g.from the metastructure data storage 1132) or to convert a data model tothe matching metastructure format.

The user interface/API 1122 may allow programmatic access to thematching metastructures representing data models in the matchingmetastructure system 1124. For example, the user interface/API 1122 mayprovide create, update, delete (CRUD) services for the matchingmetastructures, and may further control access to the metastructure datastorage 1132 (which may be through the matching metastructure system1124). The user interface/API 1122 may also provide access to previouslycreated matching metastructure schemas, such as for common ornon-proprietary data models. The user interface/API 1122 may include aweb interface, which may include a RESTful implementation of the userinterface/API, including implementations using the OData protocol.

Example 12—Matching Metastructure Definition

FIG. 12A depicts a matching metastructure definition 1200. The matchingmetastructure may be persisted, and may be stored as, or converted to, agraph representation.

The matching metastructure 1200 may have one or more data schemas 1202,1226. A data schema object 1202, 1226 generally describes the structurein which data for a data model is held in the metastructure. Forexample, the structure may include information describing the technical(e.g. data type) and semantic (e.g., what the data means, how it isformatted, how it may be used, etc.) properties of data associated withthe data model. A data schema 1202, 1226 may have multiple schemaobjects 1204 (each of which may be instantiated one or more times),multiple relationship objects 1206, or multiple virtual schema objects1208, or a combination thereof (including none).

A data schema 1202, 1226 may also have several properties. The dataschema 1202 may have an identifier property (e.g. DataSchemaID field orvariable) for uniquely identifying the data schema. The data schema 1202may have a model identifier property (e.g. ModelID field or variable)for identifying the data model (e.g. file or database schema, whichcould be in the form of a URI) described by the data schema. The dataschema 1202 may have a type property (e.g. DataSchemaType field orvariable) that indicates the type of data model represented in the dataschema 1202. Examples of different types are: a relational databaseschema, a conceptual data model, or an application program interface(API). The data schema 1202 may have a version number property (e.g.Version field or variable) indicating the version of the data schema,which may be used in versioning as described herein. The data schema1202 may have a human-understandable description property (e.g. Namefield or variable). The data schema 1202 may have a publisher property(e.g. Publisher field or variable) indicating the creator or source ofthe data schema. In some embodiments, a data schema 1202, 1226 may haveadditional or alternative properties.

A schema object 1204, 1228 generally describes a structural component ofa data model, or a structural component of a portion of a data model,represented by the data schema 1202, 1226. For example, a structuralcomponent for a database schema may be a table, or a column in a table,or a view, and so on. As another example, a structural component for anAPI may be a function call or an argument to a function call. Generally,a data schema 1202 has a schema object 1204 for all structuralcomponents identified in the data model described by the data schema.

A schema object 1204, 1228 may also have several properties. The schemaobject 1204 may have an identifier property (e.g. ObjectID field orvariable) for uniquely identifying the schema object. The schema object1204 may have a component identifier property (e.g. ComponentID field orvariable) for identifying the structural component (e.g. table in adatabase, column in a database table, function call in an API) describedby the schema object. The schema object 1204 may have a type property(e.g. ObjectType field or variable) that indicates the type of thestructural component described by the schema object 1204. Examples ofdifferent types are: a relational database table, a relational databaseattribute (e.g. column), a function in an API, or an interface parameter(e.g. argument to a function call in an API). The schema object 1204 mayhave a human-understandable description property (e.g. Name field orvariable). In some embodiments, a schema object 1204 may have additionalor alternative properties.

A schema object 1204, 1228 may reference a value list 1210. A value list1210 may have, or enumerate, a set of values 1212 that instances of theschema object 1204 that references the value list may have. In somecases, the value list 1210 may be a mutually exclusive set of values1212. Generally, a schema object 1204, 1228 associated with a value list1210 may only have the values 1212 in the value list when instantiated.As an example, a schema object 1204 describing a “date month” field mayreference a value list 1210 having values 1212 “January,” “February,”“March,” and so on. In some cases, a value list 1210 may provide a rangefor values 1212, instead of a discrete set of values. As an example, aschema object 1204 describing a “date year” field may reference a valuelist 1210 having a range of values 1212 of 1900 to 2000.

A relationship object 1206 generally describes a relationship betweenstructural components represented by schema objects 1204 of a data modelrepresented by the data schema 1202. For example, a relationship (e.g.an ontological relationship) between a database table and a column inthe table may be that the column is an “attribute of” the table. Asanother example, a relationship between an API function and a variablefor the function may be that the variable is an “argument of” thefunction. Generally, a relationship object 1206 relates two schemaobjects 1204 in a data schema 1202 (e.g. the same data schema) anddescribes the relationship or association between the schema objects.This relationship may be expressed as R(O₁, O₂, T), where R is therelationship object, O₁ is the first schema object, O₂ is the secondschema object, and T is the type of relationship between O₁ and O₂.

A relationship object 1206 may also have several properties. Therelationship object 1206 may have an identifier property (e.g.RelationshipID field or variable) for uniquely identifying therelationship object. The relationship object 1206 may have a firstschema object identifier property (e.g. Object1ID field or variable) foridentifying the first schema object 1204 (e.g. table in a database,column in a database table, function call in an API) in therelationship. The relationship object 1206 may have a second schemaobject identifier property (e.g. Object2ID field or variable) foridentifying the second schema object 1204 (e.g. table in a database,column in a database table, function call in an API) in therelationship. The relationship object 1206 may have a type property(e.g. RelationshipType field or variable) that indicates the type of therelationship between the first and second schema objects 1204. Examplesof different types of relationships are: attribute of, foreign key of,argument of, component of. The relationship object 1206 may have ahuman-understandable description property (e.g. Name field or variable).In some embodiments, a relationship object 1206 may have additional oralternative properties.

As an example, a data schema S may describe a database data model orschema. The data schema S may have a schema object O₁ describing adatabase table and a schema object O₂ describing a column in thedatabase table. Thus, a relationship object may be described as R(O₁,O₂, AttributeOfTable), where (O₁, O₂, ϵ S) for whichS.DataSchemaType=“RelationalDatabaseSchema” and O₁.ObjectType=“Table”and O₂.ObjectType=“Attribute.”

A virtual schema object 1208 is generally similar to a schema object1204, having similar properties to a schema object. A virtual schemaobject 1208 may describe a schema object 1204 from which it is derived(or multiple schema objects), which in turn describes a structuralcomponent of a data model represented by the data schema 1202. Further,a virtual schema object 1208 is generally aware of the schema objects1204 from which it is derived. For example, a virtual schema object 1208may have a source schema object property (e.g. SourceSchemaObject1ID asa field or variable) which indicates a schema object (or multiple schemaobjects) from which it was derived. Example types of virtual schemaobjects are a calculation view in a relational database (e.g. view thatcalculates averages of data across several tables), a calculation viewattribute in a relational database (e.g. a returned result for anaverage query of data across several tables), or a function in an APIthat calls multiple other functions available in the same API.

In some embodiments, a virtual schema object 1208 may describe multipleschema objects 1204, and so represent a composition or an aggregation ofthose schema objects (e.g. a virtual table that is formed from threeschema objects 1204 representing actual tables). Thus, a virtual schemaobject 1208 may act as an assembling of multiple schema objects 1204,which may be useful in mapping or aligning the data schema (e.g. 1202)with another data schema (e.g. 1226, such as when a single schema object1204 of the data schema 1202 corresponds to multiple schema objects ofthe data schema 2 1226, or vice versa). Virtual schema objects 1208 mayalso be useful for developing a rule stack 1218 for transforming one ormore schema objects 1204 to their mapped counterparts 1228 in anotherdata model 1226. In some cases, a virtual schema object 1208 may allowfor development of a rule in a particular rule language (e.g. recursiverule language as described herein) where this cannot be done, or cannoteasily be done, using the underlying schema objects 1204 for the virtualschema object.

A virtual schema object 1208 may allow for distinguishing betweenoriginal schema objects 1204 and schema objects that were developed orcreated later. Further, virtual schema objects 1208 may be used to trackor calculate statistics about alignments 1214. For example, a virtualobject 1208 may be mapped to a schema object 1228 in another data schema1226, but underlying schema objects for the virtual schema object maynot be so mapped, or may not be explicitly mapped. The virtual schemaobject 1208 may be useful to identify or track such scenarios foranalysis.

Virtual schema objects 1208 may also be used for clustering schemaobjects 1204 within a matching metastructure describing a data model.Clustering a data model may make understanding a data model easier forusers or programmers, and may improve schema mapping or alignmentprocesses. The schema objects 1204 in a matching metastructure 1200 maybe clustered using clustering technology as disclosed in the CLUSTERINGWITHIN DATABASE DATA MODELS patent application filed concurrentlyherewith, having inventors Sandra Bracholdt, Bjoern Pantel, VolkerSaggau, and Jan Portisch, and incorporated herein by reference. Clustersof schema objects 1204 may be described by virtual schema objects 1208.

The matching metastructure 1200 may have one or more alignments 1214. Analignment 1214 generally describes or identifies equivalent structuralcomponents (e.g. semantically equivalent, structurally equivalent, dataequivalent) between two data schemas, which generally describe separatedata models. An alignment 1214 may have multiple mapping objects 1216(including none). This may be expressed as A(DS_(S), DS_(T), M), where Ais the alignment, DS_(S) is the first or source data schema, DS_(T) isthe second or target data schema, and M is the set of one or moremapping objects (or, in some cases, zero or more mappings).

An alignment 1214 may also have several properties. The alignment 1214may have an identifier property (e.g. AlignmentID field or variable) foruniquely identifying the alignment. The alignment 1214 may have a firstdata schema identifier property (e.g. DataSchema1ID field or variable)for identifying the first, or source, data schema 1202 (e.g. datamodel). The alignment 1214 may have a second, or target, data schemaidentifier property (e.g. DataSchema2ID field or variable) foridentifying the second data schema 1226 (e.g. data model) that isaligned or has been mapped to the first data schema. The alignment 1214may have a human-understandable description property (e.g. Name field orvariable). The alignment 1214 may have a version number property (e.g.Version field or variable) indicating the version of the alignment,which may be used in versioning as described herein. In someembodiments, an alignment 1214 may have additional or alternativeproperties.

A mapping object 1216 generally describes an equivalence between one ormore structural components represented by schema objects 1204 of a datamodel represented by the data schema 1202 and one or more structuralcomponents represented by schema objects 2 1228 of a second data modelrepresented by the data schema 2 1226. For example, a database table ina first data model may be mapped to a database table in a different datamodel because they are deemed to be semantically equivalent (or, in atleast some cases, technically or structurally equivalent). Semanticallyequivalent structural components are structural components that have thesame or approximately the same conceptual data, even if named, stored,or organized differently within the component. For example, a databasetable named “Users” with fields “name,” “ID,” and “permissions” may besemantically equivalent to a database table named “t453_1” with fields“a”, “b,” “c,” and “d.” In at least some cases, conceptual data can beequivalent even though the datatypes associated with the data (e.g.,fields) are different between the data models, such as having a field Ain a first model having a data type of integer and a field 1 in a secondmodel having a data type of float.

A mapping object 1216 may also have several properties. The mappingobject 1216 may have an identifier property (e.g. MappingID field orvariable) for uniquely identifying the mapping object. The mappingobject 1216 may have a first schema object identifier property (e.g.Object1ID field or variable) for identifying the first, or source,schema object 1204 (e.g. table in a database, column in a databasetable, function call in an API) in the mapping. In some cases, the firstschema object identifier may be a set of multiple schema objectidentifiers from the source data schema (e.g. multiple schema objects inthe source data schema map to a single schema object in the targetschema). The mapping object 1216 may have a second schema objectidentifier property (e.g. Object2ID field or variable) for identifyingthe second, or target, schema object 1228 (e.g. table in a database,column in a database table, function call in an API) in the mapping. Insome cases, the second schema object identifier may be a set of multipleschema object identifiers from the target data schema (e.g. multipleschema objects in the target data schema map to a single schema objectin the source schema). The mapping object 1216 may have a confidenceproperty (e.g. Confidence field or variable) that indicates the strengthor correctness of the mapping between the first and second schemaobjects 1204, 1228. The confidence property may be expressed as apercentage, a normalized score, or as another value, or, in some cases,a qualitative identifier (e.g., high, medium, low). The mapping object1216 may have a human-understandable description property (e.g. Namefield or variable). In some embodiments, a mapping object 1216 may haveadditional or alternative properties.

A mapping object 1216 may reference a rule stack 1218. A rule stack 1218may be a set of one or more, optionally ordered, rules 1220 composed ofrule building blocks 1222 and having consequences 1224. The rule stack1218 (and its components 1220, 1222, 1224) may be recursive rulelanguage rules, as described herein. Generally, a rule 1220 is a firstorder logic expression that is built using the rule building blocks1222. A consequence 1224 for a rule is an action (or actions) that istaken when the rule evaluates to true. A consequence 1224 may specify avalue that is to be written to a target schema object (e.g. schemaobject 2 1228) in a target data schema (e.g. data schema 2 1226).

Generally, a mapping object 1216 defines equivalent schema objects 1204,1228 between separate data schemas 1202, 1226. Generally, a rule stack1218 describes how to translate data from the source schema object 1204to the target schema object 1228, such as identified in the mappingobject. Generally, a rule stack 1218 for a mapping object 1216 only usesschema objects 1204, 1228 from the data schemas 1202, 1226 used in thealignment 1214 with which the mapping object is associated.

The data objects (e.g. data schema 1202, schema objects 1204, etc.) inthe matching metastructure 1200 may be implemented as datatypes forvarious implementations, such as tables, classes, attributes, variables,and so on.

FIG. 12B depicts an example implementation of the matching metastructureas a database schema 1230. The example matching metastructure databaseschema 1230 may be a physical data model implemented in a databasesystem, and may store the matching metastructure objects as rows intables. The example database schema 1230 may include a data schema 1232having a DataSchema table 1232 a storing data schemas, a SchemaObjecttable 1232 b storing schema objects, an OriginalObjectsForVirtualObjectstable 1232 c storing virtual schema objects, and a relationship table1232 d storing relationship objects. The example database schema 1230may include value lists 1234 having a ValueList table 1234 a storingvalues lists and a Values table 1234 b storing values for the valuelists.

The example database schema 1230 may include an alignment 1236 having aDataSchemaAlignment table 126 a storing alignments, and a Mapping table1236 b storing mapping objects for the alignments. The example databaseschema 1230 may include rules 1238 having a Rule table 1238 a storingrules for mapping transformations, a Rule Building Block table 1238 bstoring rule building blocks for the rules, and a Consequence table 1238c storing consequences or results for the rules when triggered orsatisfied.

FIG. 12C is a diagram depicting an example 1240 matching metastructurefor two databases. A database 1 1242 may have a table 1 1244, which mayhave a column 1 1246 and a column 2 1248, and a table 2 1250. Table 11244 may be associated 1247 with table 2 1250, such as through foreignkeys. A database 2 1252 may have a table A 1254. Database 1 1242 may bealigned with database 2 1252, the process of which may have mapped 1249table 1 1244 to table A 1254.

Database 1 1242 may be represented or described in the matchingmetastructure by data schema 1 1260, which may be a data schema asdescribed for the matching metastructure herein. Similarly, database 21252 may be represented in the matching metastructure by data schema 21280. A data schema object 1260, 1280 may be implemented similar to thefollowing example code:

public class JpaeSchema{  @Id  @Column(length=2000)  public String uri; public String schemaCode;  public String schemaName;  public StringschemaVersionCode;  public String schemaVersionName;  public SchemaTypeschemaType;  public String getSchemaCode( ) {   return schemaCode;  } public void setSchemaCode(String schemaCode) {   this.schemaCode =schemaCode;  }  public String getSchemaName( ) {   return schemaName;  } public void setSchemaName(String schemaName) {   this.schemaName =schemaName;  }  public String getSchemaVersionCode( ) {   returnschemaVersionCode;  }  public void setSchemaVersionCode(StringschemaVersionCode) {   this.schemaVersionCode = schemaVersionCode;  } public String getSchemaVersionName( ) {   return schemaVersionName;  } public void setSchemaVersionName(String schemaVersionName) {  this.schemaVersionName = schemaVersionName;  }  public SchemaTypegetSchemaType( ) {   return schemaType;  }  public voidsetSchemaType(SchemaType schemaType) {   this.schemaType = schemaType; } }

Table 1 1244 may be represented in the matching metastructure by schemaobject 1 1262, which may be a schema object as described for thematching metastructure herein. Similarly, column 1 1246 may berepresented in the matching metastructure by schema object 2 1264 andcolumn 2 1248 may be represented in the matching metastructure by schemaobject 3 1266. Similarly, table 2 1250 may be represented in thematching metastructure by schema object 4 1268. A schema object 1262,1264, 1266, 1268, 1282 may be implemented similar to the followingexample code:

  public class JpaeSchemaNode {  @Id  @Column(length=2000)  publicString uri;  public String rootUri;  public String schemaNodeCode; public String schemaNodeName;  @Column(columnDefinition=“CLOB”)  @Lob public String description;  public SchemaNodeType schemaNodeType; @Column(length=2000)  public String schema_uri; } public classJpaePDMEntity extends JpaeSchemaNode{ } public class JpaeAttributeextends JpaeSchemaNode {  public boolean isKey;  public booleanisMandatory; } public class JpaePDMAttribute extends JpaeAttribute{ }public class JpaeCDMInheritance extends JpaeSchemaNode{ } public classJpaeCDMEntity extends JpaeSchemaNode{ } public class JpaeCDMAttributeextends JpaeAttribute { }

The association between table 1 1244 and column 1 1246 (e.g. column 1 asan attribute of table 1) may be represented in the matchingmetastructure as relationship object 1 1270, which may reference schemaobject 1 1262 and schema object 2 1264. Similarly, the associationbetween table 1 1244 and column 2 1248 (e.g. column 2 as an attribute oftable 1) may be represented in the matching metastructure asrelationship object 2 1272, which may reference schema object 1 1262 andschema object 3 1266. Similarly, the association 1247 between table 11244 and table 2 1250 (e.g. table 1 and table 2 linked by foreign keys)may be represented in the matching metastructure as relationship object3 1274, which may reference schema object 1 1262 and schema object 41268. A relationship object 1270, 1272, 1274 may be implemented similarto the following example code:

  public class JpaeSchemaEdge {  @Id  @Column(length=2000)  publicString uri;  public String rootUri;  public String schemaEdgeCode; public String schemaEdgeName;  public SchemaEdgeType schemaEdgeType; @Column(length=2000)  public String source_uri;  @Column(length=2000) public String target_uri;  @Column(length=2000)  public Stringschema_uri; } public class JpaeRelationship extends JpaeSchemaNode{ public Cardinality entityACardinality;  public CardinalityentityBCardinality; } public class JpaePDMRelationship extendsJpaeRelationship { } public class JpaeCDMRelationship extendsJpaeRelationship {  public boolean isADependent;  public booleanisBDependent; }

A virtual schema object 1276, as described herein for the matchingmetastructure) may reference schema object 1 1262 and schema object 41268, aggregating the two schema objects together as a single object inthe virtual schema object. A virtual schema object 1276 may beimplemented similar to the schema object example code.

Table A 1254 may be represented in the matching metastructure by schemaobject A 1282, which may be a schema object as described for thematching metastructure herein.

An alignment 1284 may represent or define the matching between database1 1242 and database 2 1252, such as mapping 1249. The alignment 1284 mayreference the data schema 1 1260 and the data schema 2 1280. Analignment object 1284 may be implemented similar to the followingexample code:

  public class JpaeSchemaAlignment{  @Id  @Column(length=4000)  publicString schemaAlignmentUri;  public String versionCode; @Column(length=2000)  public String sourceUri;  @Column(length=2000) public String targetUri;  public String description; }

The mapping 1249 may be represented in the matching metastructure as themapping object 1 1286, which may reference schema object 1 1262 in dataschema 1 1260 and schema object A 1282 in data schema 2 1280. A mappingobject 1286 may be implemented similar to the following example code:

  public class JpaeCorrespondence{  @Id  @Column(length=5000)  publicString correspondenceUri;  public String versionCode; @Column(length=4000)  public String schemaAlignmentUri; @Column(length=2000)  public String targetNodeUri; @Column(length=2000)  public String sourceSchemaUri; @Column(length=2000)  public String targetSchemaUri;  public Stringcomment; } public class JpaeCorrespondenceNode{  @Id @GeneratedValue(strategy = GenerationType.AUTO)  public UUID ID; public String versionCode;  public String comment; @Column(length=4000)  public String inputNodeUri;  @Column(length=4000) public String correspondenceUri;  @Column(length=2000)  public StringsourceSchemaUri;  @Column(length=2000)  public String targetSchemaUri; }

Example 13—Matching Metastructure Versioning

FIG. 13 depicts a version transformation example 1300 for a matchingmetastructure schema. A data schema 1 1302 may be version 1 and a dataschema 2 1306 may be version 1. An alignment 1-2 1304 may align (e.g.map) the version 1 data schema 1 1302 and the version 1 data schema 21306. The alignment 1-2 1304 may be version 1. Generally, during thelifecycle of the data schemas 1302, 1306 and the alignment 1304, thesame versions remain linked. Thus, a given version of a data schema(e.g. version 1 of data schema 1 1302) links to a given version of analignment (e.g. version 1 of alignment 1-2 1304), which links to a givenversion of the second data schema (e.g. version 1 of the data schema 21306).

Changes to any of the data schema 1 1302, data schema 2 1306, or thealignment 1-2 1304 may prompt a version change (e.g. increase).Generally, the version change applies to all linked data schemas 1302,1306 and alignments 1304, regardless of whether that schema or alignmentwas changed. Thus, scenarios where no changes were made to the otherlinked data schemas or alignments still result in changes to theirversions if the version changed for a linked data schema or alignment.For example, if Data Schema 2 changes from version 1 1306 to version 21316, both data schema 1 and alignment 1-2 will change from version 11302, 1304 to version 2 1312, 1314 even if neither data schema 1 noralignment 1-2 changed. Thus, if one or more of the data schema 1 1302,data schema 2 1306, or the alignment 1-2 1304 changes, all 1302, 1304,1306 will have their versions increased (even if that particular dataschema or alignment did not, itself, change), becoming version 2 of dataschema 1 1312 linked to version 2 of alignment 1-2 1314 linked toversion 2 of data schema 2 1316.

Increasing a version may include creating copies of the appropriate dataschemas 1302, 1306 and alignment 1304 and increasing their versionnumbers, resulting in data schemas 1312, 1316 and alignment 1314.Increasing a version may also include changing one or more properties orobjects of the data schemas or alignment 1302, 1304, 1306. Increasing aversion may include re-mapping the data schemas 1302, 1306, which may bedone through an automatic or semi-automatic process.

Generally, by maintaining consist versions of linked data schemas andalignments, the full lifecycle management of the matching metastructuremay be more accurately maintained and performed.

Example 14—Matching Metastructure Conversion

FIG. 14A is a flowchart illustrating a process 1400 for data modelconversion to a matching metastructure format or schema.

A data model representation may be obtained or received at 1402.Receiving the data model representation at 1402 may include receiving anidentifier for the data model representation, which may be used toaccess the data model representation (e.g., in a data dictionary). Alocation value may be provided along with the data model identifier, insome cases, such as a file path or a URI. In other embodiments,receiving the data model representation at 1402 may include receiving anindicator to access a database to obtain the data model representation.In other embodiments, the data model representation itself may bereceived at 1402. For example, a schema or a graph representation of thedata model may be received (or otherwise obtained) at 1402.

In some embodiments, obtaining a data model representation at 1402 mayinclude transforming a schema or data model into a graph representation,which may then be used as the data model representation in process 1400.For example, in some cases it may be more efficient to convert a graphrepresentation of a data model into the matching metastructure andconvert the original data model representation into a graphrepresentation, than to convert the original graph representationdirectly into the matching metastructure format.

A type may be identified at 1404 for the data model received at 1402. Insome embodiments, the type may be received along with the data modelrepresentation at 1402. For example, a type indicator may be provided tothe process at 1402, such as whether the type is a database schema or anAPI schema. In other embodiments, a type may be determined at 1404 basedon the source of the data model representation. For example, a datamodel representation obtained from a database may indicate the datamodel is a database schema. In other embodiments, the data modelrepresentation may be analyzed 1404 to determine the data model type.For example, a data model representation may contain a field or metadataindicating the type of data model. In other cases, the type may beidentified based on one or more structural components of the data modelrepresentation. For example, tables may be detected as structuralcomponents of the data model representation, which may be used toidentify the data model representation as a database schema.

The data model representation may be converted to the matchingmetastructure at 1406 (e.g., the metastructure having a format thatallows schemas to be converted to a “generic” or common metastructurethat provides a common format for comparing/aligning data models). Theconverting may be based on the data model type determined at 1406. Forexample, a different algorithm or process may be used to analyzedifferent data model types (e.g. different adapters or plug-ins).

Converting may include generating a data schema for the data modelrepresentation, and setting the data schema type to the data model typeidentified at 1404. One or more properties of the data schema may be setas well. Converting may further include generating schema objects forstructural components (e.g. database tables, columns, API functions,function arguments, etc.) identified in the data model representation.Structural components of the data model representation may be traversedor iterated through, with a schema object created for each structuralcomponent, until all structural components have a corresponding schemaobject created. One or more properties of the schema objects may be setas well based on their corresponding structural components in the datamodel representation.

Converting may further include generating relationship objects forlinks, connections, or associations between structural components (e.g.foreign keys between database tables, columns as attributes of databasetables, call between API functions, variables as function arguments,etc.) identified in the data model representation. Links, connections,or associations between structural components in the data modelrepresentation may be traversed or iterated through, with a relationshipobject created for each link, connection, or association, until all suchlinks, connections, or associations have a corresponding relationshipobject created. One or more properties of the relationship objects maybe set as well based on their corresponding link, connection, orassociation in the data model representation. Converting may furtherinclude generating one or more virtual schema objects, based on one ormore of the generated schema objects, which may include setting one ormore properties of the virtual schema objects.

Converting at 1406 may include generating one or more values lists forvalue definitions for structural components in the data modelrepresentation. Generating a value list may include retrieving the valueoptions from the data model representation and storing them as values ina value list in the matching metastructure schema. Generating a valuelist may further include associating the value list with one or moreschema objects generated at 1406.

The matching metastructure for the data model representation may bestored at 1408. In some embodiments, the respective data schema, schemaobjects, and other components of the matching metastructure may bestored as they are generated at 1406 as part of the converting. In otherembodiments, the complete matching metastructure for the data modelrepresentation may be stored once all schema objects and othercomponents of the matching metastructure are generated as part of theconverting. Storing may include writing the matching metastructure forthe data model to a memory or other data storage, such as in a databaseor matching metastructure representation file, as described herein. Inother embodiments, the matching metastructure may be stored as metadataobjects or objects in a metadata schema for the data model, or asinstances of object-oriented classes for the matching metastructure, asdescribed herein.

FIG. 14B is a flowchart illustrating a process 1410 for data modelmapping conversion to a matching metastructure format or schema. Thatis, a mapping may have been created using a process other than thatdescribed herein, and such mapping can be converted from the formatgenerated by the other process to the matching metastructure format orschema by the process 1410. The process 1410 for data model mappingconversion may be integrated with the process 1400 for data modelconversion to a matching metastructure format or schema.

One or more mappings between data models may be obtained or received at1412. The mappings may be received from a data model alignment ormapping process, such as may be accomplished automatically orsemi-automatically by executing, calling, or otherwise accessing theschema alignment technologies disclosed in the SCHEMA ALIGNMENT ANDSTRUCTURAL DATA MAPPING OF DATABASE OBJECTS patent application filedconcurrently herewith, having inventors Sandra Bracholdt, Volker Saggau,and Jan Portisch, and incorporated herein by reference.

In other embodiments, receiving the data model mappings at 1412 mayinclude receiving an identifier for a representation of the data modelmappings, which may be used to access a file storing the data modelmappings. A location value may be provided along with the data modelmappings identifier, in some cases. In other embodiments, receiving thedata model mappings at 1412 may include receiving an indicator to accessa database to obtain the data model mappings. In other embodiments, arepresentation (e.g. file) of the data model mappings may itself bereceived at 1412.

The data model mappings may be converted to the matching metastructureat 1414. Converting the mappings may include generating an alignment inthe matching metastructure, as described herein, for the two data modelsmapped to each other. Generating the alignment may include setting oneor more properties of the alignment. Converting the mappings may furtherinclude generating mapping objects in the matching metastructure, asdescribed herein, for the received mappings, which may include iteratingover or traversing the received mappings to generate a mapping objectfor each of the respective mappings between the data models. In someembodiments, the mappings may be received iteratively, and so eachmapping object may be generated as the mapping is received ordetermined. Generating the alignment and mapping objects may includesetting one or more of the properties of the alignment or mappingobjects as described herein.

The matching metastructure for the mappings may be stored at 1416,similar to step 1408 in process 1400 shown in FIG. 14A.

FIG. 14C is a flowchart illustrating a process 1420 for mappingtransformation conversion to a matching metastructure format or schema.The process 1420 for mapping transformation conversion is generally usedin conjunction with matching metastructure alignment and mappingobjects, as described herein. The process 1420 for mappingtransformation conversion may be integrated with the process 1410 fordata model mapping conversion to a matching metastructure format orschema.

One or more mapping transformations for mappings between data models maybe obtained or received at 1422. A mapping transformation may be used totransform a first data model of a mapping to a second, mapped data modelof the mapping. In at least some cases, a separate mappingtransformation may be needed for converting the second mapped data modelto the first data model. The mapping transformations may be similar tothe recursive rule language rules as described herein, and may bereceived or obtained from processes for recursive rule languagegeneration or retrieval as described herein. Receiving the mappingstransformations at 1422 may be similar to step 1412 in process 1410shown in FIG. 14B.

The data model mapping transformations may be converted to the matchingmetastructure at 1424. Converting the mapping transformations mayinclude generating rule stacks in the matching metastructure, asdescribed herein, for the mapping transformations. Generating a rulestack may include generating one or more rules, rule building blocks,and consequences based on the mapping transformation, or as describedherein for recursive rule language rules. Generating the rule stack andits rules, rule building blocks and consequences may include setting oneor more of the properties of the rule stack, rules, rule building blocksand consequences as described herein.

The matching metastructure for the mapping transformations may be storedat 1426, similar to step 1408 in process 1400 shown in FIG. 14A.

Example 15—Matching Metastructure Module Environments

FIG. 15A is a schematic diagram depicting an application environment fora matching metastructure module 1504, which may provide metastructureconversion and analysis functionality as described herein. Anapplication 1502, such as a software application running in a computingenvironment, may have one or more plug-ins 1503 (or add-ins or othersoftware extensions to programs) that add functionality to, or otherwiseenhance, the application. The matching metastructure module 1504 may beintegrated with the application 1502; for example, the matchingmetastructure module may be integrated as a plug-in. The matchingmetastructure module 1504 may add functionality to the application 1502for metastructure conversion and analysis, which may be displayed in auser interface or otherwise provided to a user. For example, theapplication 1502 may be a database or data modeling application, or adatabase management application, and the matching metastructure module1504 may be integrated with the database or data management applicationto provide metastructure conversion and analysis functionality.

FIG. 15B is a schematic diagram depicting a system environment for amatching metastructure module 1516, which may provide metastructureconversion and analysis functionality as described herein. The matchingmetastructure module 1516 may be integrated with a computer system 1512.The computer system 1512 may include an operating system, or otherwisebe a software platform, and the matching metastructure module 1516 maybe an application or service running in the operating system orplatform, or the matching metastructure module may be integrated withinthe operating system or platform as a service or functionality providedthrough the operating system or platform. The system 1512 may be aserver or other networked computer or file system. Additionally oralternatively, the matching metastructure module 1516 may communicatewith and provide metastructure conversion and analysis functionality, asdescribed herein, to one or more applications 1514, such as database,data modeling, or database management applications, in the system 1512.

FIG. 15C is a schematic diagram depicting a network environment 1520 fora matching metastructure module 1522, which may provide metastructureconversion and analysis functionality as described herein. The matchingmetastructure module 1522 may be available on a network 1521, orintegrated with a system (such as from FIG. 15B) on a network. Such anetwork 1521 may be a cloud network or a local network. The matchingmetastructure module 1522 may be available as a service to other systemson the network 1521 or that have access to the network (e.g., may beon-demand software or SaaS). For example, system 2 1524 may be part of,or have access to, the network 1521, and so can utilize metastructureconversion and analysis functionality from the matching metastructuremodule 1522. Additionally, system 1 1526, which may be part of or haveaccess to the network 1521, may have one or more applications, such asapplication 1528, that may utilize metastructure conversion and analysisfunctionality from the matching metastructure module 1522.

In these ways, the matching metastructure module 1504, 1516, 1522 may beintegrated into an application, a system, or a network, to providemetastructure conversion and analysis functionality as described herein.

Example 16—Additional Matching Metastructure Processes

FIG. 16A illustrates a process 1600 for generating a metadatarepresentation of a first database model. The processes 1600, 1620, 1640may be implemented by one or more computing devices comprising at leastone hardware processor and one or more tangible memories coupled to theat least one hardware processor.

A source representation of the first database model may be received at1602. The source representation may include a representation of at leasta first database table including at least a first column, the firstdatabase table representation including at least a first identifier forthe at least first database table and at least a second identifier forthe at least first column.

A first instance of a metastructure schema object datatype may begenerated at 1604 based on the first database table representation. Themetastructure schema object datatype may include a first data memberrepresenting an identifier for a database object represented by aninstance of the metastructure schema object datatype and a second datamember representing a database object type associated with the databaseobject. Generating the first instance of the metastructure schema objectdatatype may include at 1604 a assigning the first identifier of thefirst database table to the first data member of the first instance.Generating the first instance of the metastructure schema objectdatatype may include at 1604 b determining that the first identifier isassociated with a database table. Generating the first instance of themetastructure schema object datatype may include at 1604 c assigning atype identifier to the second data member of the first instanceindicating that the first instance represents a database table.

A second instance of the metastructure schema object datatype may begenerated at 1606 based on the first column representation. Generatingthe second instance of the metastructure schema object datatype mayinclude at 1606 a assigning the second identifier of the first column tothe first data member of the second instance. Generating the secondinstance of the metastructure schema object datatype may include at 1606b determining that the second identifier is associated with a column ofa database table. Generating the second instance of the metastructureschema object datatype may include at 1606 c assigning a type identifierto the second data member of the second instance indicating that thesecond instance represents a column of a database table.

The first instance of the metastructure schema object datatype and thesecond instance of the metastructure schema object datatype may bestored at 1608 in association.

FIG. 16B illustrates a process 1620 for maintaining data model mappings.A first data model may be received at 1622. The first data model mayinclude one or more structural components and one or more relationshipsbetween structural components. A first data schema for the first datamodel may be generated at 1624. The first data schema may include at1624 a a set of schema objects corresponding to the one or morestructural components of the first data model. A given schema object mayinclude a schema object identifier and a structural componentidentifier. The first data schema may include at 1624 b a set ofrelationship objects corresponding to the one or more relationships inthe first data model. A given relationship object may include arelationship object identifier, a first schema object identifier, and asecond schema object identifier.

A second data model may be received at 1626. The second data model mayinclude one or more second structural components and one or more secondrelationships between second structural components. A second data schemafor the second data model may be generated at 1628. The second dataschema may include at 1628 a a second set of schema objectscorresponding to the one or more second structural components of thesecond data model. A given second schema object may include a secondschema object identifier and a second structural component identifier.The second data schema may include at 1628 b a second set ofrelationship objects corresponding to the one or more secondrelationships in the second data model. A given second relationshipobject may include a second relationship object identifier, a thirdschema object identifier, and a fourth schema object identifier.

One or more mappings between the first data model and the second datamodel may be received at 1630. A data schema alignment may be generatedat 1632 for the first data model and the second data model. The dataschema alignment may include at 1632 a a set of alignment mappings basedon the one or more received mappings. A given alignment mapping mayinclude identifiers for one or more schema objects from the first datamodel and an identifier for a schema object in the second data model.

FIG. 16C illustrates a process 1640 for generating a metadatarepresentation of a first data model. The processes 1600, 1620, 1640 maybe implemented by one or more computing devices comprising at least onehardware processor and one or more tangible memories coupled to the atleast one hardware processor.

A source representation of the first data model may be received at 1642.The source representation may include a representation of one or morestructural components of the first data model, respectively havingidentifiers and types. One or more instances of a metastructure schemaobject datatype may be generated at 1644 based on the one or morestructural components of the source representation. The metastructureschema object datatype may include a first data member representing anidentifier for a structural component represented by an instance of themetastructure schema object datatype and a second data memberrepresenting a structural component type for a structural componentrepresented by an instance of the metastructure schema object datatype.

Generating a given instance of the metastructure schema object datatypefor a given structural component may include at 1644 a assigning a firstidentifier of the given structural component to the first data member ofthe given instance. Generating a given instance of the metastructureschema object datatype for a given structural component may include at1644 b determining a first type associated with the given structuralcomponent. Generating a given instance of the metastructure schemaobject datatype for a given structural component may include at 1644 cassigning the first type to the second data member of the giveninstance.

The one or more instances of the metastructure schema object datatypemay be stored at 1646 in association.

Example 17—Computing Systems

FIG. 17 depicts a generalized example of a suitable computing system1700 in which the described innovations may be implemented. Thecomputing system 1700 is not intended to suggest any limitation as toscope of use or functionality of the present disclosure, as theinnovations may be implemented in diverse general-purpose orspecial-purpose computing systems.

With reference to FIG. 17, the computing system 1700 includes one ormore processing units 1710, 1715 and memory 1720, 1725. In FIG. 17, thisbasic configuration 1730 is included within a dashed line. Theprocessing units 1710, 1715 execute computer-executable instructions,such as for implementing components of the processes of FIGS. 8-10,14A-C, and 16A-C, the systems of FIGS. 4, 11B and 15A-C, or thedatabases, data representations, rules and examples of FIGS. 1-3, 5-7,11A, 12A-C, and 13. A processing unit can be a general-purpose centralprocessing unit (CPU), processor in an application-specific integratedcircuit (ASIC), or any other type of processor. In a multi-processingsystem, multiple processing units execute computer-executableinstructions to increase processing power. For example, FIG. 17 shows acentral processing unit 1710 as well as a graphics processing unit orco-processing unit 1715. The tangible memory 1720, 1725 may be volatilememory (e.g., registers, cache, RAM), non-volatile memory (e.g., ROM,EEPROM, flash memory, etc.), or some combination of the two, accessibleby the processing unit(s) 1710, 1715. The memory 1720, 1725 storessoftware 1780 implementing one or more innovations described herein, inthe form of computer-executable instructions suitable for execution bythe processing unit(s) 1710, 1715. The memory 1720, 1725, may also storesettings or settings characteristics, databases, data sets, interfaces,displays, or data models or representations shown in FIGS. 1-3, 5-7,11A, 12A-C, and 13, systems shown in FIGS. 4, 11B and 15A-C, or thesteps of the processes shown in FIGS. 8-10, 14A-C, and 16A-C.

A computing system 1700 may have additional features. For example, thecomputing system 1700 includes storage 1740, one or more input devices1750, one or more output devices 1760, and one or more communicationconnections 1770. An interconnection mechanism (not shown) such as abus, controller, or network interconnects the components of thecomputing system 1700. Typically, operating system software (not shown)provides an operating environment for other software executing in thecomputing system 1700, and coordinates activities of the components ofthe computing system 1700.

The tangible storage 1740 may be removable or non-removable, andincludes magnetic disks, magnetic tapes or cassettes, CD-ROMs, DVDs, orany other medium which can be used to store information in anon-transitory way and which can be accessed within the computing system1700. The storage 1740 stores instructions for the software 1780implementing one or more innovations described herein.

The input device(s) 1750 may be a touch input device such as a keyboard,mouse, pen, or trackball, a voice input device, a scanning device, oranother device that provides input to the computing system 1700. Theoutput device(s) 1760 may be a display, printer, speaker, CD-writer, oranother device that provides output from the computing system 1700.

The communication connection(s) 1770 enable communication over acommunication medium to another computing entity. The communicationmedium conveys information such as computer-executable instructions,audio or video input or output, or other data in a modulated datasignal. A modulated data signal is a signal that has one or more of itscharacteristics set or changed in such a manner as to encode informationin the signal. By way of example, and not limitation, communicationmedia can use an electrical, optical, RF, or other carrier.

The innovations can be described in the general context ofcomputer-executable instructions, such as those included in programmodules, being executed in a computing system on a target real orvirtual processor. Generally, program modules or components includeroutines, programs, libraries, objects, classes, components, datastructures, etc., that perform particular tasks or implement particularabstract data types. The functionality of the program modules may becombined or split between program modules as desired in variousembodiments. Computer-executable instructions for program modules may beexecuted within a local or distributed computing system.

The terms “system” and “device” are used interchangeably herein. Unlessthe context clearly indicates otherwise, neither term implies anylimitation on a type of computing system or computing device. Ingeneral, a computing system or computing device can be local ordistributed, and can include any combination of special-purpose hardwareand/or general-purpose hardware with software implementing thefunctionality described herein.

In various examples described herein, a module (e.g., component orengine) can be “coded” to perform certain operations or provide certainfunctionality, indicating that computer-executable instructions for themodule can be executed to perform such operations, cause such operationsto be performed, or to otherwise provide such functionality. Althoughfunctionality described with respect to a software component, module, orengine can be carried out as a discrete software unit (e.g., program,function, class method), it need not be implemented as a discrete unit.That is, the functionality can be incorporated into a larger or moregeneral purpose program, such as one or more lines of code in a largeror general purpose program.

For the sake of presentation, the detailed description uses terms like“determine” and “use” to describe computer operations in a computingsystem. These terms are high-level abstractions for operations performedby a computer, and should not be confused with acts performed by a humanbeing. The actual computer operations corresponding to these terms varydepending on implementation.

Example 18—Cloud Computing Environment

FIG. 18 depicts an example cloud computing environment 1800 in which thedescribed technologies can be implemented. The cloud computingenvironment 1800 comprises cloud computing services 1810. The cloudcomputing services 1810 can comprise various types of cloud computingresources, such as computer servers, data storage repositories,networking resources, etc. The cloud computing services 1810 can becentrally located (e.g., provided by a data center of a business ororganization) or distributed (e.g., provided by various computingresources located at different locations, such as different data centersand/or located in different cities or countries).

The cloud computing services 1810 are utilized by various types ofcomputing devices (e.g., client computing devices), such as computingdevices 1820, 1822, and 1824. For example, the computing devices (e.g.,1820, 1822, and 1824) can be computers (e.g., desktop or laptopcomputers), mobile devices (e.g., tablet computers or smart phones), orother types of computing devices. For example, the computing devices(e.g., 1820, 1822, and 1824) can utilize the cloud computing services1810 to perform computing operations (e.g., data processing, datastorage, and the like).

Example 19—Implementations

Although the operations of some of the disclosed methods are describedin a particular, sequential order for convenient presentation, it shouldbe understood that this manner of description encompasses rearrangement,unless a particular ordering is required by specific language set forth.For example, operations described sequentially may in some cases berearranged or performed concurrently. Moreover, for the sake ofsimplicity, the attached figures may not show the various ways in whichthe disclosed methods can be used in conjunction with other methods.

Any of the disclosed methods can be implemented as computer-executableinstructions or a computer program product stored on one or morecomputer-readable storage media, such as tangible, non-transitorycomputer-readable storage media, and executed on a computing device(e.g., any available computing device, including smart phones or othermobile devices that include computing hardware). Tangiblecomputer-readable storage media are any available tangible media thatcan be accessed within a computing environment (e.g., one or moreoptical media discs such as DVD or CD, volatile memory components (suchas DRAM or SRAM), or nonvolatile memory components (such as flash memoryor hard drives)). By way of example, and with reference to FIG. 17,computer-readable storage media include memory 1720 and 1725, andstorage 1740. The term computer-readable storage media does not includesignals and carrier waves. In addition, the term computer-readablestorage media does not include communication connections (e.g., 1770).

Any of the computer-executable instructions for implementing thedisclosed techniques as well as any data created and used duringimplementation of the disclosed embodiments can be stored on one or morecomputer-readable storage media. The computer-executable instructionscan be part of, for example, a dedicated software application or asoftware application that is accessed or downloaded via a web browser orother software application (such as a remote computing application).Such software can be executed, for example, on a single local computer(e.g., any suitable commercially available computer) or in a networkenvironment (e.g., via the Internet, a wide-area network, a local-areanetwork, a client-server network (such as a cloud computing network), orother such network) using one or more network computers.

For clarity, only certain selected aspects of the software-basedimplementations are described. It should be understood that thedisclosed technology is not limited to any specific computer language orprogram. For instance, the disclosed technology can be implemented bysoftware written in C++, Java, Perl, JavaScript, Python, Ruby, ABAP,SQL, Adobe Flash, or any other suitable programming language, or, insome examples, markup languages such as html or XML, or combinations ofsuitable programming languages and markup languages. Likewise, thedisclosed technology is not limited to any particular computer or typeof hardware.

Furthermore, any of the software-based embodiments (comprising, forexample, computer-executable instructions for causing a computer toperform any of the disclosed methods) can be uploaded, downloaded, orremotely accessed through a suitable communication means. Such suitablecommunication means include, for example, the Internet, the World WideWeb, an intranet, software applications, cable (including fiber opticcable), magnetic communications, electromagnetic communications(including RF, microwave, and infrared communications), electroniccommunications, or other such communication means.

The disclosed methods, apparatus, and systems should not be construed aslimiting in any way. Instead, the present disclosure is directed towardall novel and nonobvious features and aspects of the various disclosedembodiments, alone and in various combinations and sub combinations withone another. The disclosed methods, apparatus, and systems are notlimited to any specific aspect or feature or combination thereof, nor dothe disclosed embodiments require that any one or more specificadvantages be present or problems be solved.

The technologies from any example can be combined with the technologiesdescribed in any one or more of the other examples. In view of the manypossible embodiments to which the principles of the disclosed technologymay be applied, it should be recognized that the illustrated embodimentsare examples of the disclosed technology and should not be taken as alimitation on the scope of the disclosed technology. Rather, the scopeof the disclosed technology includes what is covered by the scope andspirit of the following claims.

What is claimed is:
 1. A computing system comprising: at least onehardware processor; at least one memory coupled to the at least onehardware processor; and one or more computer-readable storage mediastoring computer-executable instructions that, when executed, cause thecomputing system to perform operations comprising: receiving a sourcerepresentation of a first database model, wherein the sourcerepresentation comprises a first database table representation of atleast a first database table, the at least a first database tablecomprising at least a first column, the first database tablerepresentation comprising at least a first identifier for the at least afirst database table and at least a second identifier for the at least afirst column; generating a first instance of a metastructure schemaobject datatype based at least in part on the first database tablerepresentation, the metastructure schema object datatype comprising afirst data member representing an identifier for a database objectrepresented by an instance of the metastructure schema object datatypeand a second data member representing a database object type associatedwith the database object, wherein generating the first instance of themetastructure schema object datatype comprises: assigning the at least afirst identifier for the at least a first database table to the firstdata member of the first instance; determining that the at least a firstidentifier is associated with a database table; and assigning a typeidentifier to the second data member of the first instance indicatingthat the first instance represents a database table; generating a secondinstance of the metastructure schema object datatype based on arepresentation of the at least a first column, wherein generating thesecond instance of the metastructure schema object datatype comprises:assigning the at least a second identifier for the at least a firstcolumn to the first data member of the second instance; determining thatthe at least a second identifier is associated with a column of adatabase table; and assigning a type identifier to the second datamember of the second instance indicating that the second instancerepresents a column of a database table; and storing the first instanceof the metastructure schema object datatype and the second instance ofthe metastructure schema object datatype in association.
 2. Thecomputing system of claim 1, the operations further comprising:generating an instance of metastructure relationship object datatypebased on the first database table representation and the representationof the at least a first column, the metastructure relationship objectdatatype comprising a first data member representing an identifier for afirst database object represented by an instance of the metadatastructure schema object datatype, a second data member representing asecond identifier for a second database object represented by aninstance of the metadata structure schema object datatype, and a thirddata member representing a relationship type for the first databaseobject and the second database object, wherein generating the instanceof metastructure relationship object datatype comprises: assigning afirst identifier of the first instance of the metastructure schemaobject datatype to the first data member of the first instance of themetastructure relationship object datatype; assigning a secondidentifier of the second instance of the metastructure schema objectdatatype to the second data member of the first instance of themetastructure relationship object datatype; determining that the firstidentifier is associated with a database table; determining that thesecond identifier is associated with a column of the database table; andassigning a type identifier to the third data member of the instance ofthe metastructure relationship object datatype indicating the secondinstance of the metastructure schema object datatype is a column of thefirst instance of the metastructure schema object datatype; and storingthe instance of the metastructure relationship object datatype inassociation with the first instance and second instance of themetastructure schema object datatype.
 3. The computing system of claim1, the operations further comprising: generating a third instance of themetastructure schema object datatype based on a second database table inthe source representation, wherein the second database table isassociated with the at least a first database table in the sourcerepresentation, wherein generating the third instance of themetastructure schema object datatype comprises: assigning a thirdidentifier of the second database table to the first data member of thethird instance; determining that the third identifier is associated witha database table; and assigning a type identifier to the second datamember of the third instance indicating that the second instancerepresents a column of a database table; generating an instance ofmetastructure relationship object datatype based on the first databasetable representation and the representation of the at least a firstcolumn, the metastructure relationship object datatype comprising afirst data member representing an identifier for a database objectrepresented by an instance of the metadata structure schema objectdatatype, a second data member representing a second identifier for asecond database object represented by an instance of the metadatastructure schema object datatype, and a third data member representing arelationship type for the first database object and the second databaseobject, wherein generating the instance of metastructure relationshipobject datatype comprises: assigning a first identifier of the firstinstance of the metastructure schema object datatype to the first datamember of the first instance of the metastructure relationship objectdatatype; assigning a second identifier of the third instance of themetastructure schema object datatype to the second data member of theinstance of the metastructure relationship object datatype; determiningthat the first identifier is associated with a database table;determining that the second identifier is associated with a column ofthe database table; and assigning a type identifier to the third datamember of the instance of the metastructure relationship object datatypeindicating the first instance of the metastructure schema objectdatatype is in association with the second instance of the metastructureschema object datatype; and storing the instance of the metastructurerelationship object datatype and the third instance of the metastructureschema object datatype in association with the first instance and secondinstance of the metastructure schema object datatype.
 4. The computingsystem of claim 1, the operations further comprising: generating a firstinstance of a metastructure virtual schema object datatype based on thefirst instance of the metastructure schema object datatype, themetastructure virtual schema object datatype comprising a first datamember representing an identifier for a database object represented bythe first instance of the metastructure schema object datatype, a seconddata member representing a database object type associated with thedatabase object, and a third data member representing an identifier forthe first instance of the metastructure schema object datatype, whereingenerating the first instance of the metastructure virtual schema objectdatatype comprises: assigning the at least a first identifier for the atleast a first database table to the first data member of the firstinstance; determining that the at least a first identifier for the atleast a first database table is associated with a database table;assigning a type identifier to the second data member of the firstinstance indicating that the first instance represents a database table;and assigning the identifier for the first instance of the metastructureschema object datatype to the third data member; and storing the firstinstance of the metastructure virtual schema object datatype inassociation with the first instance of the metastructure schema objectdatatype.
 5. The computing system of claim 1, the operations furthercomprising: generating a first instance of a metastructure virtualschema object datatype based on the first instance of the metastructureschema object datatype, the metastructure virtual schema object datatypecomprising a first data member representing an identifier for a databaseobject represented by the first instance of the metastructure schemaobject datatype, a second data member representing an identifier foranother database object represented by the second instance of themetastructure schema object datatype, a third data member representing adatabase object type associated with the database object, a fourth datamember representing another database object type associated with theanother database object, a fifth data member representing an identifierfor the first instance of the metastructure schema object datatype, anda sixth data member representing an identifier for the second instanceof the metastructure schema object datatype, wherein generating thefirst instance of the metastructure virtual schema object datatypecomprises: assigning the at least a first identifier for the at least afirst database table to the first data member of the first instance;determining that the first identifier is associated with a databasetable; assigning a type identifier to the second data member of thefirst instance indicating that the first instance represents a databasetable; assigning the at least a second identifier for the at least afirst column to the third data member of the first instance; determiningthat the at least a second identifier for the at least a first column isassociated with a column of a database table; assigning a typeidentifier to the fourth data member of the first instance indicatingthat the second instance represents a column of the database table;assigning the identifier for the first instance of the metastructureschema object datatype to the fifth data member; and assigning theidentifier for the second instance of the metastructure schema objectdatatype to the sixth data member; and storing the first instance of themetastructure virtual schema object datatype in association with thefirst instance of the metastructure schema object datatype.
 6. Thecomputing system of claim 1, wherein the at least a first column in theat least a first database table is associated with a first set of valuesin the source representation, the operations further comprising:generating an instance of a metastructure value list datatype based onthe first set of values, the metastructure value list datatypecomprising a first data member representing an identifier for a databaseobject represented by the second instance of the metastructure schemaobject datatype, and one or more additional data members representingvalues for the second instance of the metastructure schema objectdatatype, wherein generating the instance of the metastructure valuelist datatype comprises: assigning the identifier for the secondinstance of the metastructure schema object datatype representing the atleast a first column to the first data member; and assigning the firstset of values to the one or more additional data members of theinstance; and storing the instance of the metastructure value listdatatype in association with the second instance of the metastructureschema object datatype.
 7. The computing system of claim 1, theoperations further comprising: generating a first instance of ametastructure data schema datatype based on the source representation,the metastructure data schema datatype comprising a first data memberrepresenting an identifier for a data model representation and a seconddata member representing a data model type associated with the datamodel representation, wherein generating the instance of themetastructure data schema datatype comprises: assigning a modelidentifier of the source representation to the first data member of thefirst instance of the metastructure data schema datatype; determiningthat the source representation is associated with a database data model;and assigning a type identifier to the second data member of the firstinstance of the metastructure data schema datatype indicating that thefirst instance of the metastructure data schema datatype represents adatabase; storing the first instance of the metastructure data schemadatatype in association with the first instance and the second instanceof the metastructure schema object datatype; and wherein storing thefirst instance of the metastructure schema object datatype and thesecond instance of the metastructure schema object datatype inassociation comprises: storing the first instance of the metastructureschema object datatype in association with the first instance of themetastructure data schema datatype; and storing the second instance ofthe metastructure schema object datatype in association with the firstinstance of the metastructure data schema datatype.
 8. The computingsystem of claim 7, the operations further comprising: receiving a secondsource representation of a second database model, wherein the secondsource representation comprises a representation of at least a seconddatabase table, the representation of the at least a second databasetable comprising at least a third identifier for the at least a seconddatabase table; generating a second instance of the metastructure dataschema datatype based on the second source representation, wherein thegenerating the second instance of the metastructure data schema datatypecomprises: assigning a second model identifier of the second sourcerepresentation to the first data member of the second instance of thedata schema metastructure datatype; determining that the second sourcerepresentation is associated with a second database data model; andassigning a second type identifier to the second data member of thesecond instance of the metastructure data schema datatype indicatingthat the second instance of the metastructure data schema datatyperepresents a second database; generating a third instance of themetastructure data schema datatype based on the representation of the atleast a second database table in the second source representation;generating an instance of a metastructure alignment datatype based onthe first instance of the metastructure data schema datatype and thesecond instance of the metastructure data schema datatype, themetastructure alignment datatype comprising a first data memberrepresenting an identifier for an instance of the metastructure dataschema datatype, and a second data member representing an identifier foranother instance of the metastructure data schema datatype, wherein thegenerating the instance of the metastructure alignment datatypecomprises: assigning a first identifier of the first instance of themetastructure data schema datatype to the first data member of theinstance of the metastructure alignment datatype; and assigning a secondidentifier of the second instance of the metastructure data schemadatatype to the second data member of the instance of the metastructurealignment datatype; and storing the second instance of the metastructuredata schema datatype, the third instance of the metastructure dataschema datatype, and the instance of the metastructure alignmentdatatype in association with the first instance of the metastructuredata schema datatype.
 9. The computing system of claim 8, the operationsfurther comprising: receiving mapping data for the source representationand the second source representation, wherein the mapping data comprisesa first identifier for the at least a first database table in the sourcerepresentation and a second identifier for the at least a seconddatabase table in the second source representation; generating aninstance of a metastructure mapping object datatype based on the mappingdata, the metastructure mapping object datatype comprising a first datamember representing an identifier for an instance of the metastructureschema object datatype in a first data model representation, and asecond data member representing an identifier for another instance ofthe metastructure schema object datatype in a second data modelrepresentation, wherein generating the instance of the metastructuremapping object datatype comprises: obtaining a source identifier for thefirst instance of the metastructure schema object datatype based on thefirst identifier in the mapping data; assigning the source identifierfor the first instance of the metastructure data schema datatype to thefirst data member of the instance of the metastructure mapping objectdatatype; obtaining a target identifier for the third instance of themetastructure schema object datatype based on the second identifier inthe mapping data; and assigning the target identifier for the thirdinstance of the metastructure data schema datatype to the second datamember of the instance of the metastructure mapping object datatype; andstoring the instance of the metastructure mapping object datatype, inassociation with the instance of the metastructure alignment datatype.10. The computing system of claim 9, wherein the mapping data isreceived from a database schema alignment process for the sourcerepresentation and the second source representation.
 11. The computingsystem of claim 9, wherein the first instance or the third instance ofthe metastructure data schema datatype is used instead of an instance ofa metastructure virtual schema object datatype for an instance of avirtual schema object that references one or more schema objects. 12.The computing system of claim 11, wherein the instance of themetastructure virtual schema object datatype is for an instance of anaggregate virtual schema object.
 13. The computing system of claim 9,the operations further comprising: executing an ETL process transferringdata from a first database represented by the first instance of themetastructure data schema datatype to the second database represented bythe second instance of the metastructure data schema datatype, via theinstance of the metastructure alignment datatype and the instance of themetastructure mapping object data type in association with the instanceof the metastructure alignment datatype.
 14. The computing system ofclaim 9, the operations further comprising: generating an instance of ametastructure rule stack datatype for the instance of the metastructuremapping object, the metastructure rule stack data type comprising one ormore rules, one or more rule building blocks, and one or moreconsequences; and, storing the instance of the metastructure rule stackdatatype, in association with the instance of the metastructure amapping object datatype.
 15. The computing system of claim 14, whereingenerating an instance of the metastructure rule stack data typecomprises generating the one or more rules, one or more rule buildingblocks, and the one or more consequences, which comprises: retrieving adata transformation specification in a domain specific language; parsingthe data transformation specification to determine at least a first ruleand at least a second rule specified in the data transformationspecification; parsing the data transformation specification todetermine at least a first action specified in the data transformationspecification; determining that the at least a second rule referencesthe at least a first rule; and generating nested conditional statementsrepresenting conditions of the at least a first rule and the at least asecond rule.
 16. The computing system of claim 15, wherein generatingthe one or more rules further comprises: determining an executionformat; compiling the nested conditional statements to the executionformat; and storing the compiled nested conditional statements inexecution format in association with the instance of the metastructurerule stack datatype.
 17. The computing system of claim 16, theoperations further comprising: executing an ETL process transferringdata from the first database represented by the first instance of themetastructure data schema datatype to the second database represented bythe second instance of the metastructure data schema datatype via theinstance of the metastructure alignment datatype and the instance of themetastructure mapping object in association with the instance of themetastructure alignment datatype, wherein executing the ETL processfurther comprises: executing the compiled nested conditional statementsin execution format to transform data in the first database for storagein the second database.
 18. A method, implemented by a computing systemcomprising at least one hardware processor and at least one memorycoupled to the at least one hardware processor, the method comprising:receiving a source representation of a first database model, wherein thesource representation comprises a first database table representation ofat least a first database table comprising at least a first column, thefirst database table representation comprising at least a firstidentifier for the at least a first database table and at least a secondidentifier for the at least a first column; generating a first instanceof a metastructure schema object datatype based on the first databasetable representation, the metastructure schema object datatypecomprising a first data member representing an identifier for a databaseobject represented by an instance of the metastructure schema objectdatatype and a second data member representing a database object typeassociated with the database object, wherein generating the firstinstance of the metastructure schema object datatype comprises:assigning the at least a first identifier for the at least a firstdatabase table to the first data member of the first instance;determining that the at least a first identifier for the at least afirst database table is associated with a database table; and assigninga type identifier to the second data member of the first instanceindicating that the first instance represents a database table;generating a second instance of the metastructure schema object datatypebased on a representation of the at least a first column, whereingenerating the second instance of the metastructure schema objectdatatype comprises: assigning the at least a second identifier for theat least a first column to the first data member of the second instance;determining that the at least a second identifier is associated with acolumn of a database table; and assigning a type identifier to thesecond data member of the second instance indicating that the secondinstance represents a column of a database table; and storing the firstinstance of the metastructure schema object datatype and the secondinstance of the metastructure schema object datatype in association. 19.The method of claim 18, further comprising: generating a first instanceof a metastructure relationship object datatype based on the firstdatabase table representation and the representation of the at least afirst column, the metastructure relationship object datatype comprisinga first data member representing an identifier for a first databaseobject represented by an instance of the metastructure schema objectdatatype, a second data member representing a second identifier for asecond database object represented by an instance of the metastructureschema object datatype, and a third data member representing arelationship type for the first database object and the second databaseobject, wherein generating the instance of metastructure relationshipobject datatype comprises: assigning a first identifier of the firstinstance of the metastructure schema object datatype to the first datamember of the first instance of the metastructure relationship objectdatatype; assigning a second identifier of the second instance of themetastructure schema object datatype to the second data member of thefirst instance of the metastructure relationship object datatype;determining that the first identifier is associated with a databasetable; determining that the second identifier is associated with acolumn of the database table; and assigning a type identifier to thethird data member of the instance of the metastructure relationshipobject datatype indicating the second instance of the metastructureschema object datatype is a column of the first instance of themetastructure schema object datatype; and storing the instance of themetastructure relationship object datatype in association with the firstinstance and second instance of the metastructure schema objectdatatype.
 20. The method of claim 18, further comprising: generating afirst instance of a metastructure virtual schema object datatype basedon the first instance of the metastructure schema object datatype, themetastructure virtual schema object datatype comprising a first datamember representing an identifier for a database object represented bythe first instance of the metastructure schema object datatype, a seconddata member representing a database object type associated with thedatabase object, and a third data member representing an identifier forthe first instance of the metastructure schema object datatype, whereingenerating the first instance of the metastructure virtual schema objectdatatype comprises: assigning the at least a first identifier of the atleast a first database table to the first data member of the firstinstance; determining that the at least a first identifier of the atleast a first database table is associated with a database table;assigning a type identifier to the second data member of the firstinstance indicating that the first instance represents a database table;and assigning the identifier for the first instance of the metastructureschema object datatype to the third data member; and storing the firstinstance of the metastructure virtual schema object datatype inassociation with the first instance of the metastructure schema objectdatatype.
 21. The method of claim 18, wherein the at least a firstcolumn in the at least a first database table is associated with a firstset of values in the source representation, the method furthercomprising: generating an instance of a metastructure value listdatatype based on the first set of values, the metastructure value listdatatype comprising a first data member representing an identifier for adatabase object represented by the second instance of the metastructureschema object datatype, and one or more additional data membersrepresenting values for the second instance of the metastructure schemaobject datatype, wherein generating the instance of the metastructurevalue list datatype comprises: assigning the identifier for the secondinstance of the metastructure schema object datatype representing the atleast a first column to the first data member; and assigning the firstset of values to the one or more additional data members of theinstance; and storing the instance of the metastructure value listdatatype in association with the second instance of the metastructureschema object datatype.
 22. The method of claim 18, further comprising:generating an instance of a metastructure data schema datatype based onthe source representation, the metastructure data schema datatypecomprising a first data member representing an identifier for a datamodel representation and a second data member representing a data modeltype associated with the data model representation, wherein generatingthe instance of the metastructure data schema datatype comprises:assigning a model identifier of the source representation to the firstdata member of the instance of the metastructure data schema datatype;determining that the source representation is associated with a databasedata model; and assigning a type identifier to the second data member ofthe first instance of the metastructure data schema datatype indicatingthat the first instance of the metastructure data schema datatyperepresents a database; and storing the instance of the metastructuredata schema datatype in association with the first instance and thesecond instance of the metastructure schema object datatype; and whereinstoring the first instance of the metastructure schema object datatypeand the second instance of the metastructure schema object datatype inassociation comprises: storing the first instance of the metastructureschema object datatype in association with the instance of themetastructure data schema datatype; and storing the second instance ofthe metastructure schema object datatype in association with theinstance of the metastructure data schema datatype.
 23. One or morenon-transitory computer-readable storage media comprising:computer-executable instructions that, when executed by a computingsystem comprising at least one memory and at least one hardwareprocessor coupled to the at least one memory, cause the computing systemto receive a source representation of a first database model, whereinthe source representation comprises a first representation of at least afirst database table comprising at least a first column, the at least afirst database table representation comprising at least a firstidentifier for the at least a first database table and at least a secondidentifier for the at least first column; computer-executableinstructions that, when executed by the computing system, cause thecomputing system to generate a first instance of a metastructure schemaobject datatype based on the first database table representation, themetastructure schema object datatype comprising a first data memberrepresenting an identifier for a database object represented by aninstance of the metastructure schema object datatype and a second datamember representing a database object type associated with the databaseobject, wherein the computer-executable instructions that generate thefirst instance of the metastructure schema object datatype comprise:computer-executable instructions that, when executed by the computingsystem, cause the computing system to assign the at least a firstidentifier of the at least a first database table to the first datamember of the first instance; computer-executable instructions that,when executed by the computing system, cause the computing system todetermine that the at least a first identifier is associated with adatabase table; and computer-executable instructions that, when executedby the computing system, cause the computing system to assign a typeidentifier to the second data member of the first instance indicatingthat the first instance represents a database table; computer-executableinstructions that, when executed by the computing system, cause thecomputing system to generate a second instance of the metastructureschema object datatype based on a representation of the at least a firstcolumn, wherein the computer-executable instructions that generate thesecond instance of the metastructure schema object datatype comprise:computer-executable instructions that, when executed by the computingsystem, cause the computing system to assign the at least a secondidentifier of the at least a first column to the first data member ofthe second instance; computer-executable instructions that, whenexecuted by the computing system, cause the computing system todetermine that the at least a second identifier is associated with acolumn of a database table; and computer-executable instructions that,when executed by the computing system, cause the computing system toassign a type identifier to the second data member of the secondinstance indicating that the second instance represents a column of adatabase table; and computer-executable instructions that, when executedby the computing system, cause the computing system to store the firstinstance of the metastructure schema object datatype and the secondinstance of the metastructure schema object datatype in association. 24.The one or more non-transitory computer-readable storage media of claim23, further comprising: computer-executable instructions that, whenexecuted by the computing system, cause the computing system to generateat first instance of metastructure relationship object datatype based onthe first database table representation and the representation of the atleast a first column, the metastructure relationship object datatypecomprising a first data member representing an identifier for a firstdatabase object represented by an instance of the metadata structureschema object datatype, a second data member representing a secondidentifier for a second database object represented by an instance ofthe metastructure schema object datatype, and a third data memberrepresenting a relationship type for the first database object and thesecond database object, wherein generating the instance of metastructurerelationship object datatype comprises: computer-executable instructionsthat, when executed by the computing system, cause the computing systemto assign a first identifier of the first instance of the metastructureschema object datatype to the first data member of the first instance ofthe metastructure relationship object datatype; computer-executableinstructions that, when executed by the computing system, cause thecomputing system to assign a second identifier of the second instance ofthe metastructure schema object datatype to the second data member ofthe first instance of the metastructure relationship object datatype;computer-executable instructions that, when executed by the computingsystem, cause the computing system to determine that the firstidentifier is associated with a database table; computer-executableinstructions that, when executed by the computing system, cause thecomputing system to determine that the second identifier is associatedwith a column of the database table; and computer-executableinstructions that, when executed by the computing system, cause thecomputing system to assign a type identifier to the third data member ofthe instance of the metastructure relationship object datatypeindicating the second instance of the metastructure schema objectdatatype is a column of the first instance of the metastructure schemaobject datatype; and computer-executable instructions that, whenexecuted by the computing system, cause the computing system to storethe instance of the metastructure relationship object datatype inassociation with the first instance and second instance of themetastructure schema object datatype.
 25. The one or more non-transitorycomputer-readable storage media of claim 23, further comprising:computer-executable instructions that, when executed by the computingsystem, cause the computing system to generate a first instance of ametastructure virtual schema object datatype based on the first instanceof the metastructure schema object datatype, the metastructure virtualschema object datatype comprising a first data member representing anidentifier for a database object represented by the first instance ofthe metastructure schema object datatype, a second data memberrepresenting a database object type associated with the database object,and a third data member representing an identifier for the firstinstance of the metastructure schema object datatype, wherein thecomputer-executable instructions that generate the first instance of themetastructure virtual schema object datatype comprise:computer-executable instructions that, when executed by the computingsystem, cause the computing system to assign the at least a firstidentifier of the at least a first database table to the first datamember of the first instance; computer-executable instructions that,when executed by the computing system, cause the computing system todetermine that the at least a first identifier of the at least a firstdatabase table is associated with a database table; computer-executableinstructions that, when executed by the computing system, cause thecomputing system to assign a type identifier to the second data memberof the first instance indicating that the first instance represents adatabase table; and computer-executable instructions that, when executedby the computing system, cause the computing system to assign theidentifier for the first instance of the metastructure schema objectdatatype to the third data member; and computer-executable instructionsthat, when executed by the computing system, cause the computing systemto store the first instance of the metastructure virtual schema objectdatatype in association with the first instance of the metastructureschema object datatype.
 26. The one or more non-transitorycomputer-readable storage media claim 23, wherein the at least a firstcolumn in the at least a first database table is associated with a firstset of values in the source representation, further comprising:computer-executable instructions that, when executed by the computingsystem, cause the computing system to generate an instance of ametastructure value list datatype based on the first set of values, themetastructure value list datatype comprising a first data memberrepresenting an identifier for a database object represented by thesecond instance of the metastructure schema object datatype, and one ormore additional data members representing values for the second instanceof the metastructure schema object datatype, wherein thecomputer-executable instructions that generate the instance of themetastructure value list datatype comprise: computer-executableinstructions that, when executed by the computing system, cause thecomputing system to assign the identifier for the second instance of themetastructure schema object datatype representing the at least a firstcolumn to the first data member; and computer-executable instructionsthat, when executed by the computing system, cause the computing systemto assign the first set of values to the one or more additional datamembers of the instance; and computer-executable instructions that, whenexecuted by the computing system, cause the computing system to storethe instance of the metastructure value list datatype in associationwith the second instance of the metastructure schema object datatype.27. The one or more non-transitory computer-readable storage media ofclaim 26, further comprising: computer-executable instructions that,when executed by the computing system, cause the computing system togenerate a first instance of a metastructure data schema datatype basedon the source representation, the metastructure data schema datatypecomprising a first data member representing an identifier for a datamodel representation and a second data member representing a data modeltype associated with the data model representation, wherein thecomputer-executable instructions that generate the instance of themetastructure data schema datatype comprise: computer-executableinstructions that, when executed by the computing system, cause thecomputing system to assign a model identifier of the sourcerepresentation to the first data member of the first instance of themetastructure data schema datatype; computer-executable instructionsthat, when executed by the computing system, cause the computing systemto determine that the source representation is associated with adatabase data model; and computer-executable instructions that, whenexecuted by the computing system, cause the computing system to assign atype identifier to the second data member of the first instance of themetastructure data schema datatype indicating that the first instance ofthe metastructure data schema datatype represents a database; andcomputer-executable instructions that, when executed by the computingsystem, cause the computing system to store the instance of themetastructure data schema datatype in association with the firstinstance and the second instance of the metastructure schema objectdatatype; and wherein the computer-executable instructions that storethe first instance of the metastructure schema object datatype and thesecond instance of the metastructure schema object datatype inassociation comprise: computer-executable instructions that, whenexecuted by the computing system, cause the computing system to storethe first instance of the metastructure schema object datatype inassociation with the first instance of the metastructure data schemadatatype; and computer-executable instructions that, when executed bythe computing system, cause the computing system to store the secondinstance of the metastructure schema object datatype in association withthe first instance of the metastructure data schema datatype.